Am I going insane!?!?!?! Help!!!?

Ok so I'm 14 and I havent slept in weeks. I either get 3-4 hours of sleep or don't sleep at all. Im having terrifying dreams and im hallucinating. Like I hear or see something that's not even there. It's keeping me from sleeping cuz I'm always freaked out and paranoid. Im always so cautious now and I'm always worried and self conscious. Like the kind of hallucinations I had last night was I was trying to sleep but I kept hearing these muffled noises and breathing so I looked up and I saw this black thing in the corner so I put my head under my pillow an then after awhile I looked up and it was gone. I've had worse though. And the dreams I have are terrifying. There so realistic that I have to ask someone if it really happened. I've been sick for two weeks with an on and off high fever and dizziness and nausea. Could that be the problem. If someone knows whats wrong with me please help. I'm sorry this is sorta long. Please and thank you.