Anyone got any ideas on why certain drugs affect me strangely?

[PuffinMuffins]

So basically I've been using drugs for a long time, but I guess i never really got a clear reading on how certain drugs affected me due to literally constantly being on an opioid (mostly heroin) in addition to those drugs for about a decade. I'm recovered as far as consistent use goes but I'm still doing the weekend/dabbler thing.
I suspect my brain chemistry has changed dramatically because pre-addiction I was a very high energy, curious, opinionated kid and I'm now sort of "too mellow" leaning toward apathetic, lethargic and complacent.

Here's what I've noticed:

With little to no tolerance to meth (having not done it for years, and having not done it frequently in the past) I have to do 3+ times more than everyone else in my circle to get effects and still don't easily get "spun" or truly high. I feel more energetic and can think more clearly and articulate myself and my feelings better, speech is more natural and I can recall words more easily than when I'm sober and in a constant state of fog. But upon snorting 30 mg at a time every 6-8 hours even for days I'm still reasonable and pretty well undetectable, whereas peers with similar tolerance can do 10 mg at a time with noticeable effects.

I can take literally. 25 mg of xanax and practically pass out, with residual confusion and irritability for 20+ hours.

Weed either puts me into a state of more confusion and mild irritability (due to thinking/ processing being even more slowed) or pleasant moderate sedation). The same strain can produce different effects at different times.

Dxm, even taken at therapeutic doses, throws me into delirium. No idea what's going on, everything looks fuzzy, speaking is really difficult.

Alcohol doesn't even get me drunk anymore, I get buzzed and then upon coming "down" feel physically sick and get oddly high blood pressure and dizziness.

It's just strange since everything but meth used to affect me differently. It's always taken a lot of meth for me to feel effects, but not nearly to this degree. It just seems weird to me, given I never used any of these drugs in excess. Anyone got any ideas why?

 

[MrRoot]

Well I used opioids for 7 years and stimulants didn't do much for me when I was using in terms of euphoria and even now after abstaining for half a year they don't do that much. One exception for this is 3-FEA which works nicely at normal doses, but that works more on serotonin than dopamine.

I need pretty much double the normal dose of MDMA to roll when comparing the times when I didn't do opioids at all. Same goes for psychedelics.

DXM and similars don't do anything else than suppress cough for me.

I don't get euphoria from coke.

Benzos don't do much unless I take them enough to induce amnesia so it isn't worth it.

Lyrica doesn't do much.

I blame opioids for lot of this as well as being on Abilify injections until recently but this isn't too bad as because of this I grew bored to a plenty of drug types and now I abstain from everything but MDMA (or similar), psychedelics and 3-FEA and I use them quite responsible except for last weekend when it was Midsummer's Eve here and I used plenty of those.