I have problems with sleeping, help?!

1. Very often, I'll be on the verge of sleep, and I'll begin twitching uncontrollably. The only way it will stop is if I concentrate on holding my body still and thinking deeply that I won't twitch anymore.
2. In the past 5 years, I've probably remembered glimpses of a handful of dreams. I know that everybody dreams even if they don't remember them a lot, but it is truly a rare occasion if I can remember even a solitary word or image from a dream.

Paranoid Schizophrenia runs in my family, I have anxiety issues, an intense case of depression, as well as slight rage problems, I smoke marijuana almost everyday and have for a while [I've self tested to see if this was the problem; it doesn't matter if I've not smoked in months or if I smoke 3 times a day, nothing changes] and Post-traumatic Stress Disorder from being raped repeatedly at a young age; I'm throwing this in because I don't know if this information could help you guys figure out what the hell is wrong.