If you really want to fall asleep, get over the counter diphendramine (aka Sominex, "night time sleep aids", etc), 50 mg, gelcaps. I had a horrible time falling and staying asleep period, even before vaping. I no longer drink caffeine... if I do, I do it in tiny, tiny amounts. Just too sensitive. When I want to go to sleep, I pop two of those, and it's nighty-night in about 30 to 45 minutes. Only downside is I'm super groggy in the mornings. Ironic in that I can't touch coffee. 