Just saw this thread. I'm gonna take a shot here.
I see a pretty clear indication that you (JJ) grew-up in a shame-based household. Your parents had a strict image of what you should be as their child, and when you veered from that image, you were shamed for it. There may never have been any violence, but, if this is true, it's certainly a form of emotional abuse. Shame is the root of a lot of types of disorders.
So, emotionally demoralized and diminished, you increasingly turned to things that would help ease that pain, a typical response of many. Addictions are often borne from this need. For some, they are the one thing that keeps some people from suicide, because it gives them a way to manage their pain. In your case, I don't know if marijuana was really a gateway drug -- I think you would have gotten addicted to anything that killed the pain. Going to stronger drugs was an obvious choice, as they worked better, as you learned about them.
OK, so, fine, let's say you have PTSD, ADHD, and any number of other diagnoses and acronyms assigned to you. First, as one poster mentioned previously, self-diagnosis without professional corroboration is foolish -- in the same way that doing surgery on yourself, or being your own lawyer is foolish. You can't be 100% objective.
Regardless of this, the diagnoses matter less than what you are feeling, than what's eating at you. The drugs will kill the pain for a time, but they tend to kill all real emotion. It will be very hard to have authentic experiences of love, compassion, empathy, etc. as well. And, no matter how hard you try and stuff the pain down, it will eventually come-back to haunt you, time and time again, by short-circuiting your life's pursuits.
And, most obviously, such strong drugs will damage your brain, making true recovery even more difficult over time, and potentially lead to early physical disablement, mental impairment, and death.
No judgement here -- it's a simple choice of two worlds. If you remain on the drugs, you are choosing a shortened and diminished life, but one where your inner pain is controlled and where you won't have to consciously deal with it. But you will have to get used to a life similar to what you've had since your parents made you leave home. Your emotional trauma will do nothing but sabotage every attempt you make at trying to normalize your life -- including reinforcing your addictions and perpetuating an increasingly destructive cycle.
If you decide to deal with the emotional trauma that is causing all of this self-destructive behavior, you will suffer for a time. You will have to encounter the shame and feel -- really feel -- all of the pain. You'll have to work hard at it. You'll have to quit all of the drugs and recover from all of the addictions, over time, in order to be clear-enough to do this work. Why do this? So that you can be yourself, instead of living a lie or living in a fog to escape. So that, someday, you can look your father in the eye and tell him, without fear or shame, that you thought that at least some of what he did and said was wrong. And so on.
You have to make a choice. You may make one choice today and change your mind at some later point. You have to be ready to do recovery. And, you have to be ready and willing to take responsibility for the state of your life and yourself. No matter what was done to you, no matter how badly you feel, and no matter how many mistakes you make or things you screw-up, you need to be able to say, "Yes, I'm responsible for that" -- and learn to do it without destroying yourself as a person.
OK, long enough. My two cents. ;) Hope this made sense.