How do I stay clean?

Ive seen people stay clean for months years and im sitting here like wtf I can’t make it to a week today was supposed to be day seven but I’m back at zero and my gf saw and she isn’t mad but she’s disappointed and she told one of my friends because she knows how to deal with my *** and now they’re both disappointed and I feel like *** and how tf do I get clean my highest is six *** days im just not strong enough Ive been doing this since I was nine years old im almost fourteen and guess what my parents don’t notice anything they don’t care about me at all and Ik this my mum has said I ruined her life my being born idk anymore sorry im being annoying I’ll just shut up and suck it up like I always do cause I don’t matter