Late-Diagnosed but sometimes I doubt it? Anyone else feel the same?

I was diagnosed 5 months ago after realizing that it wasn't normal that I have been wondering since a young age if I was autistic. I mentioned that to a friend as if everyone thinks that and sure enough found out that I wasn't. I have been able to make friends but it has been difficult. From a young age I was completely mirror peoples personalities, interests and even their speech to fit in. It worked for a while but got me into situations that I'm not proud of as I've been pretty easy to manipulate. I guess what really drove me to get a diagnosis is that since I was a child, I have struggled with hitting myself when I feel really sad or upset and it feels like something just comes over me and I can't stop. Luckily I have a partner that supports me and has unfortunately had to physically restrain me.

When I got diagnosed I was honestly surprised. I thought I would get told I have ADHD or something. She told me that initially she thought I was neurotypical but after speaking to me for a couple days and me explaining my thoughts and way of viewing the world that I actually am Autistic. Sometimes I wonder if I'm faking it but I feel like it's caused a lot of confusion. But at the same time it makes sense? Idk I guess I'm just rambling now and am wondering if anyone feels the same? People think I have it all together but my parents wont even move states (even though they really want to) because they know I'm struggling a lot mentally and I'm literally a 26 year old woman. Feels kind of pathetic sometimes. Well... anyways that's it.