My moms having a relationship with a 19 year old, I’m 18 and she’s 37.. there’s so many things going on, to start- we don’t have a relationship it’s more of a “acquaintance”. My dad passed away when I was 6 and I just have so much hate towards her, anyways. I had a KB about 2 months ago and I invited friends.. there was this guy I’ve had a crush on and he came. My mom stayed inside while we were outside (it was something small) anyways, at one point he went inside to use the restroom, took awhile to come out so I went inside and I see him chatting with my mom. I got annoyed just because it’s her but didn’t think much of it. Word got out that they exchanged numbers and they’ve been dating. I couldn’t believe it, didn’t believe it until I asked her and she confirmed. I’m disgusted and so embarrassed, I want to run away. I never want to look at her again..

I don’t even know what to do, any advice

Edit- reason I hate my mom is because she cheated on my dad & he passed away.