Advice desperately needed

I’ve been with my boyfriend for 3 years since I was 15. We were each other’s first everythings and he is and will always be special to me.

Our relationship was amazing for the first year and a half but since then it’s been terrible, we argue all the time and we’re on the edge of breaking up every week. It’s incredibly toxic and draining and I know I need to get out but I can’t. Every time I say I want to break up he messages me and calls me or turns up at my house constantly begging and promising and I always give in even though I know it won’t work. Every time I tell myself I’ll stay strong, I block him and try to do other things but I always end up going back. When we’re together it’s amazing, we get on so well and make the most amazing memories and I always think about that and how much I’ll miss that.

The time I spend with him is the only time I’m really happy so I don’t know how to get through it. I don’t have a supportive friend group around me and I’m currently trying to save money to move out because I hate my family that much. When we break up I’ve managed weeks sometimes before getting back together but I feel like I have no one to talk to properly or spend time with and I feel so lonely and have nothing in my life that makes me happy. I end up having the mindset that the happy times I spend with him are worth the misery the rest of our relationship brings me.

I just don’t know how to actually get through the break up and get over him, I’ve tried everything and I need to get out but I can’t. It’s ruining my life. I appreciate anyone that takes the time to read so many boring paragraphs🙄 Desperate for any advice pls girls I’m really struggling🧡