So you had a liver transplant? Interesting. Maybe the newer liver has different enzymes & things that might metabolize stuff differently for you now. Interesting to ponder though.
I didn't mean to be insulting, I was genuinely just shocked. lol Never seen "surrounded" spelled like that before & was more confused, because most modern computers & phones show a red line under a word if it' s not spelled right, so people can just proof-read & auto-correct anything in red. But I didn't call you any names or harp on you for it, just thought I'd call it out. If I'm mis-spelling anything significant, people can let me know, I don't mind. lol Tone is hard to read over the internet though, so I could see how one might of taken it the wrong way and for that apologize.
I actually love tramadol & opioids. Specifically tramadol & diacetylmorphine. I've been an opioid addict for almost 20 years now. Absolutely wonderful drugs for my depression. The itch is part of the high!

Histamine release & all.
But even on tramadol & heroin, I'd have the one-off experiences where I'd feel like shit, get nauseous, dysphoric. But I'd say 95% of the time it was enjoyable, but that other 5%, it would some times make me feel pretty gross. I think this happens mostly with people who don't have tolerances. Opioids can feel rather boring & drab when you first start them but after a few days of using is when the euphoria & bliss really starts to shine.
Same happens with buprenorphine some days, even after taking it every day for over 8 years now. I'll have those one-off days where it'll just make me feel like shit. Actually buprenorphine makes me feel like shit quite often compared to the aforementioned two opioids.
The one & only DXO experience on Erowid is a negative one, full of side effects it sounds like -
https://www.erowid.org/chemicals/dxm/dxm_info3.shtml
So you're probably not alone in having dysphoric/negative experiences with DXO unfortunately. There's a synth-tek in that link as well that might be of interest to you (most likely not, since it's for DXO).
I'll have to respond more to the rest when I'm more cognizant.
I've had some insane near death-like experiences on DXM & cannabis. I've also experience what I refer to as "Paranormal" type experiences & such on DXM. Like strange unexplainable things happening, even with sober witnesses around to see it. Psychedelics don't even have this property IMO. But something about DXM messes with the fabric of reality in some ways. And I use to use it a lot for ritual purposes & manifesting things. Causes a lot of synchronicities too (or maybe just delusions, but at least the delusions are fun & make life interesting lol). I think William White wrote about DXM's purported "paranormal" properties, if you haven't seen the William White DXM FAQ.