Constant relapsing

I’m 20 years old and have been using some combination of one drug or another, gambling, and drinking for 4 years now and I keep getting sober then relapsing, I’ll go a day, a week, a couple months, but never a year or years of sobriety. Ill get bored or stressed and I’ll relapse; I’ll get on and off drinking, and gambling; I was on and off all kinds of drugs until I was 19, destroying and repairing then destroying and repairing again my physical and mental health, finances, relationships, etc. I’ve done extensive personal work to treat all the issues that caused the addictions, and I don’t really have any mental pain, but there’s still always that itch in my brain that makes me wanna get ridiculously high amounts of dopamine not possible without drugs alcohol and gambling. Please help