Question on why some sleep meds make me feel europhic before bed?

So the title is a misleading. I have severe insomnia. My sleep medicine doctor has me on 10mg zolpidem. I take the zolpidem 20 minutes before my desired sleep time then take 5mg melatonin 10 minutes before my desired sleep time. Then I take 100mg of benadryl 5 minutes before my desired sleep time.

I ofcourse do not fall asleep in that 20 minute timeframe. I lay in bed and try to fall asleep. I do however after taking the zolpidem and right after taking the melatonin feel a little euphoric. I suddenly feel like nothing is serious and that everything is kind of blah. I also have bad constipation most of the time and usually have to go no. 2 after taking all of these pills. What could be causing this?