didnt read the whole thing because Im sleep deprived. but if your taking some medications then it's extreemly likely that one of them will inhibit CYP2D6 or some might be 2D6 substrates.
I dont think this fellow is highly deficient in anything.
This dose is 5mg/kg and at that dose I have felt very similar effects. Were looking at 120lbs people thats pretty light. I've had weird CEVs. In fact, at 6 mg/kg I once thought I entered the world of TRON and fixed their server.
As far as duration: You took the gels at 2. I've had times where it takes 3 hours for the gels to hit the system good. It takes at least an hour for those things to release and for me to feel the come up start. Then from there DXM often can take another hour to settle in. I've had times where the robo gels took 90 minutes and the come up another 90 until I was fully blown. Plus, assuming you may have had lunch, you might have slowed the release with a little food left in the stomach. And Dextromethorphan is supposed to truly last for 6 hours, so the 11 PM woozy'ness was normal. The morning "Afterglow" effects also sound accurate.
You are fine. You responded completely normal for your weight.
You were able to speak and communicate which is possible at that level. If you were enzyme deficient, you would be completely plastered still for that time. And your friend likely woulda had a hard time reaching you.
Proceed cautiously, be sure to calculate your dosage. DXM responds pretty normally for most people but you just need to do the math first.
Interestingly enough, I also weigh about 120, and I recently did 255 mg. Although I didn't experience quite as strong cevs as you, I did have some pleasantly strong dissociation and cevs while listening to music. also a bit of nausea, but it completely went away when I layed down.
DXM was the first drug I tripped on, I liked it, but not too much, but then I tried Ketamine, and realized I like dissociatives, and DXM just happens to be the shittiest one, haha. An alright report, though I must inform you that LSD and acid are the same thing...