what sort of drugs have you been using? they have different timescales. when i was in rehab for crack and heroin i was completely joyless, i couldn't laugh. that was mostly an effect of the crack cos i was on the dark way longer and was not joyless the whole time. i first laughed after about 4 weeks.
sleep improved surprisingly quickly.
the first actively feeling good took at least 3 months. i was super super mentally unstable though up to 6 months when i got medicted for my CPTSD. i had been using drugs of one form or another daily since i was 16 so there was a lot of healing to do.
i had residual psychosis from the crack for about 6 months too though it diminished quite quickly.
it will depend on your nutrition, whether you're exercising, if you're doing other things to benefit your mental health. so there are lots of factors in your control tha