I need help, please

I am very sorry for the quality of my English, this is my third language. I am really desperate at this point and I needed to read stories from people who may have been in my position. I've been lurking this sub for a long time, I don't want to post my story from my official account, so here it is.

My husband of 35 years had an EA and a PA with a co-worker of (25 F). For six months, he refused to change jobs arguing that he is paid very well, during which time I noticed a change in his behaviour. He became distant, cold and rude to me and to our five- and three-year-old children. I, as his wife and life partner for ten years, deserved an explanation, so I asked him several times what was going on, if there was someone else, but he denied everything and moved further away from me. His behaviour became more atrocious each time, he treated me with disdain, with disgust, with contempt.

After another big fight, where he was again late for a romantic dinner I organised at his favourite restaurant, I noticed he spent more time on his phone and became more reserved, before going to work we used to give kisses, text each other during his work hour, share songs to listen to in his free time, just talk and he stopped.I checked his phone, everything was in Microsoft Teams with his AP, there were phrases like: ‘every moment with them without you is meaningless’, ‘I love you, you are everything I ever wanted’, ‘making love to you in the hood outdoors was the best thing that ever happened to me, being inside you makes me wish I was alive’, and what almost killed me was the phrase that said ‘you are everything I wanted and never expected to find, I love you, I am yours’.

When I first confronted him, he denied everything, I told him I saw the evidence on his phone, this made him even more angry, he put some clothes in his backpack while I tried to get him to talk to me, he went to his sister's house. I later found out that his sister covered for him and that he actually only came to sleep at her house around 2am. I felt even more deceived and betrayed by his sister's complicity in my husband's infidelity. This was a woman I comforted for months when her boyfriend of seven years cheated on her with her friend, let cry on my shoulders and was able to do the same to me. When my husband left for the first time, I was in an anxiety attack, I cried for three hours straight. I called him, but he didn't answer my calls, I sent him hundreds of messages that he should think about our children and that this was not the man I married. After three days of no contact and not even wanting to see our children, my husband finally came home and admitted the affair. However, he did so in a manner completely disconnected from his feelings and without apologising. Instead, he recounted the events as if he was talking about something he had seen on television rather than something he had actively participated in. I shouted at her, I demanded she tell me, why? I asked him: where did we go wrong? He didn't answer. I didn't want to lose my family, my children were devastated after not seeing their father for three days.

I did everything I could to recover a marriage after EA and PA. I read books on the subject, went to couples therapy, and tried to be more present in our relationship. I even proposed moving cities and changing jobs to put the past behind us and start over. But my husband was unwilling to quit or change jobs, and his lack of involvement and refusal to change only increased my pain and sense of betrayal.

The worst was when I went on a trip to another country to visit my family, I had planned it for a year. I didn't want to go, he insisted and as we had had a good week and I couldn't get the money back, I agreed. I was in contact with him all the time for the first few days, my heart sank when I saw through the location tracking app that he was at the bar where they used to meet the PA. I called him immediately, he rejected me didn't answer my calls, stayed till 4 am at that place, my heart just died, something broke inside me, if he wanted to cheat on me again at least he had to have the decency to turn off his location. why should I endure this pain? His constant rejections for six months, the cruel way he yelled at me, mocked me and belittled me with his words. How he ignored me for six months, how he refused to do the work in therapy and filled his mouth saying that if I had done it, he would have divorced me and kept the children. Ten years of love and dedication to this man, even when the sex was bad and he ignored me every time I wanted to talk about it.

I didn't care anymore, and that led me to make an impulsive decision. I downloaded some dating apps I wanted attention and validation from other men. I had sexual encounters with six APs, and without protection with AP#5 and he AP#6 I experimented with drugs with the last one. I felt like a different person, a wild version of myself who just wanted to live, to regain some freedom, I wanted sex.

I extended my stay for another week, I think he knew something was wrong as I only asked to speak to the kids and asked him about them, there were no more verification calls, I didn't ask questions about what he did that night, and I deactivated my location, when he asked me why I did it I told him it was no longer needed, and closed the subject. When I came back things were no better, I didn't feel guilty, I felt that the person who did all those things was a wild version of me, so I slept with my husband after three months of D-day#1. But things didn't get better, I felt trapped in my house with him, so I started to look at the surrounding men with different eyes, and I admit that on the 13th of December I got in the car of an acquaintance from the gym and gave him oral sex and he made me finish with his hands, we didn't have full sex, as we didn't have protection and he didn't want to do it without feeling safe. This man flirted with me twice a year ago, so I avoided him with all my might because I had no other time to work out. And this time, I was the one who sought him out and flirted shamelessly with him for three days before we got into his car. I wanted a united family, I wanted us to come out stronger as a couple and better than before. But now all I feel when I see him is that I kissed him after I had performed oral sex on another man in a car and felt no remorse.

On 24 December, he wrote me a letter to apologise for everything, he cried, it was the first time he had ever cried. He told me that the last month he was distant, he realised that I was leaving work later and trying to get in earlier so as not to be with him, that I stopped cooking for everyone, something I love with all my strength, that every time I look at his face my eyes don't shine like before that I don't write him messages during work, that I don't send him funny videos anymore that I stopped telling him that I love him and that he can be next to me anywhere and I don't recognise his presence, and that when we made love for the first time after three months he didn't feel like I did, that I didn't look him in the face. He told me that he doesn't want to lose his family, he admitted that when he was away he left our children with his sister and that he met with the AP he said he felt he owed her closure, that things with her are over for good. That she didn't answer my calls, as she was in pain at the time, and that when I extended my trip she felt she had broken something, and that when she went to meet me at the airport and I didn't run into her arms as usual, she knew she was one step away from losing me, that she listens to the podcasts I recommended, is reading the books I told her months ago to read. That he will do what he needs to do in therapy, and that putting up the Christmas tree, having to take care of the food and presents by himself and without me was one of the worst pains he ever felt in his life. That I didn't look him in the face anymore, that I didn't propose to take a bath together, that I didn't lie on his lap when we watched a movie and that I wasn't even interested in making our movie nights, that I didn't play music to clean up singing anymore killed him.  He apologised to me, took the blame, and that he is going to tender his resignation on 12 January at work.That he now felt the damage he caused and that he will work all his life for us.

I don't know what to do, I need some advice. Words of encouragement.