I Cant Stop

Hello, i've been trying to quit porn for a long time and i really dont think i can do it. I was first introduced to it ate age 7 by an older cousin and it's been in my life ever since. I'm 19 now and i have not had sex, i got to bed once with a girl but suffered from ED due to excessive porn viewing. I've also just got out of an 8 month drug rehabilitation program due to marijuana and cocaine abuse. When i was younger i would watch regular porn but as time went by the things i watched were weirder. The last porn fetish i got into was interracial and cuckold porn and i cant stop watching it. The thing is that after i watch it i feel like shit but i keep doing it. It also made me feel extremley insecure about my penis size making me think its too small even though i know its average(5.5in). But i keep obssesing over this. Im still going to that rehab center and they're therapists there but there are also other patients and this is way too embarrasing for me to talk about. I've tried to stop masturbating and watching porn because i want to have a normal life but i feel that it will never happen so there is no point in even trying to stop. I feel like this is the last resort because i really dont know what else to do. PLEASE, if you have any advice or you can relate to my story and talk about your own experience it would really help me. Thanks!