i don't mean to generalize, and of course we're all a mixed soup. i just wasn't aware that SPD could really feel ' stabbing / intolerable pain', or at least not consistently. nor really that many 'happy' memories.
i'm almost envious of your ability to do that. so many times i see films of people going nuts becuase they're in love and ache, or of lovers who are fighting for each other etc and i wish i could experience some of that passion.
so if your worst feeling is intolerable pain, maybe (i humbly submit) feeling nothing is maybe even worse on an intellectual level.
you don't mention (or maybe i misread) what the source of your pain is. just that you see a psych for it, take meds, drugs and consider suicide.
never taken opioids, curious what effect it gives you? i find if i pop a xanax it will pretty much completely flatten me out - if i stay on it a week or month whatever was bothering me also becomes nebulous. (and a lot of sleep)
you're drinking while posting, so maybe the pain is a bit magnified in your writing, nothing wrong with that.
think u have to at some point address the underlying cause of the pain, of the addiction, or both. sometimes the addiction ends up being the cause of the pain.
there are tools you psychologist should have given you, and that with practice i would think could lessen the effects of even PTSD memories. simple things like replaying the offending memory and changing it to be harmless or bizarre, if you do this regularly it should lessen it's effects as you're physically changing the content and the way your brain stores / links that data.
suicide is always an option. lord knows i'd bet many of us carry around our 'exit' in one form or the other just in case we decide to make the trip. i can't say if it's right (or the right time) for you. however will say that (so far) - the next day after not doing it has always led to something worth surviving for, mostly.
you say you're a musician, i'm in a similar field - that alone (doing your art well) is probably a pretty good reason.