My boyfriend has poor hygiene and it's destroying me

Like the title says, my boyfriend has very poor hygiene, in all accounts, oral body and hair. we've been together for almost 5 years and it's been a persistent issue.

He has dermatitis (untreated) and very bad dandruff and dry skin, which literally causes him to "flake" all over the place, his shoulders are always covered in white dots which are yes, dead skin cells. He always shows up to my house unwashed, with greasy hair and smelling like B.O, which I do nag him about, as I honestly hate having to kiss and hug him in that condition.

I on the other hand am very anal about hygiene in myself. I brush my own teeth 3 times a day, I do an "everything shower" every single morning and finish with a thorough skincare routine, and quite honestly, I haven't had a blemish or a bad skin day in almost years now. For me, this stems from insecurity. I look back at my teenage self who had acne, bad teeth and frizzy hair, and I go out of my way to correct that. I always get told from my family and friends that I take good care of myself, and I'm proud of that, and I want to pass even a little bit of this self care off to my boyfriend.

The thing is, he's such a sweet and lovely guy, one of the kindest people I have ever met. He always checks in on me, and is very affectionate and emotionally intimate, and was there for me when people I was close to passed away. He's a bit shy, a big goofball and is very social. I do love him very much as a person, but his hygiene is making me lose some attraction to him. However, when he's showered, moisturized and smelling good I am attracted to him, although getting him to that point can be quite hard.

When he's over at my place he only showers once every other day, and I have to nag him to get him to brush his teeth, or even wash his face and moisturize (which as someone with an actual skin condition I think he should be!) he tends to wear the same clothes for days at a time, and doesn't always brush his teeth, which makes me a nag when i have to drag him to the bathroom to do so.

I do love my boyfriend, he's a perfect guy other than his hygiene. I just wish it wasn't an issue, because it is pretty important to me too stay clean and smelling good. I hate how shallow I sound, but I just don't know what to do. I'm not his mom so I don't want to have to nag him to do basic things, but I can't kiss him when his breath smells and his dandruff get all over me. I might have to have some kind of intervention with him or something, because it's getting to a point where I'm starting to resent him for it.

Edit:

I will be having a heart to heart with with him this weekend, I've received some good advice here and I think this needs to be fixed asap. I will update then.

Edit 2:

so, my boyfriend and I had a chat over the weekend, he seemed a little embarrassed and I felt like I was scolding him, but I told him how important this was to me, and that I wasn’t saying this to embarrass him but because I care. I asked him why he doesn’t see hygiene as a priority, and it genuinely seemed to him that he didn’t see himself as being unhygienic, as this state of being was just very normal to him. I expressed that I would appreciate more of an effort from him, as I put in so much effort, and the reason I look the way I do is because of that, but because I’m “lucky” or “genetically blessed” as he might think. He said he knows that, but I wanted to hammer it in his head that he should use me a positive example of self care, and take of my tips.

As the day went on he was very eager to try and prove to me he was willing to change, he went of to brush his teeth and had a shower with me on the same day, and the next day he had a shower and brushed his teeth and moisturized, and we even had a little spa day where He used some products I brought him for Christmas, his skin was very smooth and clear, and he smelled very nice. I showed him I was more attracted to him like this by complimenting how good he smelled, and hugging him.

I didn’t have sex with him (I’m in my period and I’m also prepping for surgery, I don’t wanna get into that, but basically I’m very low energy right now) but it wasn’t because I was grossed out by him, he didn’t seem to mind, and we just cuddled a lot and spoke about the future, I think I need to give him time to let this sink in, to really prove to me that he can keep up these positive changes.