Sleep after drinks

In the recent months I’ve been having an awful lot of trouble falling asleep if I’ve been drinking. My sleep has been bad in general, but if I’ve had 4-7 beers I can’t fall a sleep until there’s 2 hours left until I have to wake up. I quit weed too so that might have something to do with it. I don’t use stimulants, and I usually only manage to fall asleep right away if I’m near blacking out. Why? What do I have to do