I’m sorry about how you were treated. That was fucked up and you didn’t deserve it.
I don’t think it’s over for you, it’ll just be difficult. You’re clearly able to overcome (presumably with effort and time) some of what you talk about since this is pretty well written.
Alcohol is pretty hazardous on all levels (I assume that’s what you cite as an addiction) but if you need pot to function, I see no problem with that besides it being another expense. It’s probably worth finding a support group in your area with respect to the alcoholism, though.
As far as I know, low IQ, insofar as we treat it as a credible concept at all, doesn’t correspond to not being able to do things, but it just taking longer to learn them. That’s probably not much of a consolation with respect to all that you’ve been through, but it’s relevant for looking forward because it means you don’t need to write things off as being something “for smarter people,” though there are definitely circumstances where the extra time it takes could make something not viable (like needing more time in college representing a significantly greater financial burden, possibly).
I think you can do it. Just remember that there is no shame in leaning on others; We’re a social, cooperative species.
Speaking for myself as someone who was dismissive, my best contribution to the answers here is that it’s reductionist to a seriously misleading extent. It seems like you have a couple of conditions contributing to your struggle, but it all gets reduced to “your number is too low.” As others have alluded to, how much of that is your adhd? How much is from some condition you may have that hasn’t been diagnosed because you have been unsupported throughout your life? I don’t think anyone is denying that you have real neurological conditions that hinder you, they just doubt low IQ as being a meaningful description of what you’re facing compared to something that gives a better causal explanation.