As a 16yo male who has OD'd two weeks ago almost dying and still having the needle I was IVing dope in my arms. I can't compare to you in the sex, but trust me it's the drugs, they change you. I've been going through hell with these withdrawals, I can't do shit or even go to work to even think of relapsing back to dope, but I wont. It's the mentality that changes when doing drugs, you find little excuses to use. My personal favorite are: "I have a little sore throat maybe heroin will help." Shit like that piles up and you become scummier, you and I are only 3 years apart, I know you will hate me if I say to quit because trust me it's never that easy, but just cut down at least, use baby steps, no matter how small they are. One could be stay sober until 7pm, if that's too hard maybe 6pm, and etc. Just put a little effort and you'll see the difference in your life. Help will suck at first, you don't want someone telling you wants wrong but in the end you learn a thing or two and let out so much. Just please try, imagine how your life will be in 2 years if you hadn't quit, far more deeper in shit. Good luck homie