Anxiety, thats what. Im so sorry, just two months ago i was this way. Do you have a significant other or good family member you live with? In may i was waking up every 45 minutes violently shaking, it would wake my fiance up and he would get up and rub my back for 3-5 minutes and it really helped. Im unmedicated atm but have been on valium numerous times. Valium originally was a muscle relaxer but when your muscles relax it calms the anxiety, a back rub is a great temporary cure until you can meet with a treatment provider.
Do you know what this fear is about? If you do, or even if not, i am lately a firm believer in positive affirmations. Write them down and repeat them throughout the day "i will get great sleep tonight" "i am not afraid" "i am safe" etc, counteract the negative thoughts, even if you dont believe them and soon it starts working and you will believe them.
I will be thinking of you, i know how troubling this can be