afraid to fall asleep

i am afraid to fall asleep. i am not able to eat very much (NOT on a diet), withdrawing from longterm marijuana use, heavy grief, extreme isolation.

i am only sleeping a couple hrs a night right now. when i begin to fall asleep, i am jolted back awake again. this happens all night. i don't feel safe at night. when i see light in the window, i feel so relieved. i am afraid of a) my heart stopping while asleep. b) having a brain anyrism (sp). c) someone messing with me while asleep. i live alone. even tho i know i'm alone, i am still very afraid that someone will mess with me while sleeping. i am aware this is irrational. it doesn't stop the fear. i also can't sleep with my back to the rest of my room. i have to face my room, just in case there is someone there, then i will be ready. i feel a sensation that someone is there when my back is turned. i fear i will be sleeping, then i will feel someone tap my back, or pull my covers off, then i will turn around and no one will be there. that has never happened.

Hi, StoneFace! Have you taken a look through the OCD and anxiety forums? Those sound like they might be intrusive thoughts. No one is a professional psych here, though. Maybe there are meds that might help you and therapy too.
I thinking having a good workout during the day and maybe taking some fresh air might help you sleep.

Have you tried to relax and stop over thinking? Maybe your fear was triggered by the anxiety you have. That’s why you have a hard time to sleep better. When I am anxious and stressed I also had a hard time in sleeping too. My friend used to introduce Yuen method to me since before I had stress issues. What excites me more in doing this is that I feel more optimistic and relaxed after the session. When I had a session with Paul (YM practitioner), he helped me restore my energy by clearing all the issues in my life. After that I can really feel the effects of the energy healing. This process really helps me to get into well-being. From then on, I have a better sleep and I don’t become more negative in life.

It sounds like Marijuana withdrawal, to me.

I had this when I quit smoking, myself.
I couldn't sleep, I had all kinds of paranoia... every noise could wake me up, because I was never really asleep. I was jumpy, I was irritated... People say you can't be addicted to THC, but I beg to differ. I was used to a certain level of it being in my system constantly and the lack thereof created a withdrawal effect.

It passed in about a month and half or so... but it was hard. I also got terrible body aches and headaches.

I recommend lots of water and cranberry juice, also dark teas, like black tea before bed, hot. It helped, though until the THC was out of mys system I didn't get good sleep.
You could try getting some sleep aids from a doctor. Best to be upfront about the whole situation. They can be amazingly understanding about it, and can give you something to help or recommend an herbal substitute that can strip the THC and help you drift off a little better.