Weed can bring back psychedelic highs that are disipating but a month later is a bit hard to understand for me as real LSD is usually swept away after a week or two tops (even the psychological shift) so unless your experiencing PTSD from a bad experience, im at a loss for explanation on this. I would take HJ420's advice and give it a break altogether and see how it effects you after some time and of course start slow and small. No weed tollerance can = a hell of a trip. Ive had daydream halucinations of out of body experiences and the like when smoking a good dose of THC after my tollerence has tanked (not like psychedelics but more along the lines of disasociatives, very unique).
On a side note, i rarely enjoy smoking pot with people as much as i do alone, i find it a great meditation tool and something to make normal recreational activities so much more interesting. Pot and Socializing never went together well for me unless it was combo-ed with benzos or booze.
LSD and psyches in general can cause massive shifts in the mind, maybe you just dont enjoy pot socially anymore.
Hard to pin, interesting case though.
Cheers