I'm sorry about what's going on at your household. I'm in a similar situation, as I can't stand talking to my mom about anything or else she gets angry with me. If I mention anything about mental health, she'll just say my problems are because of something else and that there is nothing wrong with me, even though I'm struggling and needed to go to emergency due to these issues.
I know this may seem hard, but you'll be gone in 10 months to college. Just 10 months. It may seem long, I know, but things will get better. I don't know about you, but now that I am away from my mom, things are a lot better. I still struggle with her, because of technology and stuff, but other than that... things will get better.
I hope you and your girlfriend can also figure something out.