I am really depressed because of my bad habbits

Hello everyone, I am a college student and I am in my last year, I like do coding and learn new things but I quit physical activities and games in my school and It make me weaker and also I do masterbate a lot watching 18+ content which rot my mind completely. Now I know all that but I can't do any thing I tried so many time to change my self but I come back to zero😔. I am very stressed also I like a girl in my college and stayed with her but she also just used me. I don't care about it but it also make my mood worse sometimes.Please help me and give me direction and some advice 🥲