Hey Bitflipper,
Currently on venlafaxine for depression, smoked a few trucks of pot in my younger years but quit 20 years ago.
Falling a sleep without pot will be hard for you now probably, just by you told your brain you can't without it.
Is it that you need to calm down in your head ?
There's exercises for that if your brain keeps 'running high speed', every now and then that stupid relax excersize realy saves me going down into very dark periods.
Melatonine is a harmless and available to everyone sleep help pil, and ofcourse no coffee in the evening.
What helps me a lot is just walking 30 minutes, once or twice a day, and if I can do a little sports....while walking your brain generates 'dopamine' which makes you happy.
Anyway, wishing you best and get help if you should need it.
Talk to people and let them help you, they really want to.
Hang in there !