I know I shouldn’t use drugs to cope, but it feels like nothing matters anymore

I've already been through two breakups that were really rough. The first relationship lasted about a year and a half, the second one just four and a half months. My last girlfriend broke up with me four days ago. She said I'm too negative and that my depression was affecting her. I also struggle with OCD. I never wanted to dump my issues on her, sometimes I just needed to say that I was feeling low and wanted to talk.

With my first ex I acted horribly and I really wanted to learn from that, to be better for myself and for whoever came next.

In the past, I was addicted to tramadol, benzos, Lyrica, and sleeping pills. Tramadol was the worst for me. I became so independent on it. I also tried speed once while I was with my first ex and I couldn’t stop thinking about that amazing feeling for months. I know addiction runs in my family, and I know I have that tendency too. But now, it feels like nothing is stopping me anymore. I hate socializing, I get deeply attached to one person, and I feel like I was made to destroy myself.

So yeah, my girlfriend broke up with me 4 days ago and I connected that pain to my first breakup. It hit the same part of my brain, and it completely messed me up. Then I found out she unblocked her ex-boyfriend the next day she left me. The first thought I had was to buy speed again, because I felt like my life already lost meaning. Like, screw it, why not just give in to addiction again?

I know deep down that I want help, that I could get better if I really tried. But I also feel like I’m pure chaos, like once I touched drugs, there’s no going back. I already bought the speed. I’m very careful with money, and now I’m stuck between not wanting to waste it and not wanting to destroy myself again.

I talked with my ex yesterday and we agreed to give us some time, maybe talk again once we’re both more stable. But I can already feel myself slipping back into self-destruction with drugs. I’m disappointed in myself and the whole world, but it’s all my fault anyway.

I don’t think rehab would help, because it’s not that I can’t stop if I want to, it’s my mental health that’s killing me.

Thanks for reading. Insights?