At night I get really strange and insane?

During the day I'm like any normal person. I behave fine i can do any thing with no problem. I can watch any tv show or movie with out freaking out. But around like 7 I start to get weird. I get really hyper and i have alot of energy. Then around 10 it starts getting alot worse. I start getting even more hyper and I say the weirdest stuff with out thinking. I get crazy ideas and every idea I think of I do. Then at 2 is when it gets really bad. I get asked if I'm high every time I am sleeping over with some one who isnt used to my crazyness at night. Like I start jumping around and I get scared to like I get deeply convinced that there is some killer in the house. Once I was at the computer at 3 and I kept looking under the desk cause I was certin that the girl from the grudge was under it. I jump at every sound. I get kinda OCD like I can't stand when people are really close to me. And some patterns (like on a picture) annoy me and bother me and I can't look at it. I get weird thoughts. And I think of every single thing in my life. Sometimes I get really depressed when I think, Sometimes I even cut myself. I feel the need to exercise randomly. I'll give myself a hair cut. But the thing is I never am tired. I'll try laying down but I can't sleep. I dont get tired till 6 am. It happens every night. Then I'll wake up after I finally fall asleep and I'll be like "why the he'll did I do that?!" and I'll be completely sane. Like right now I'm in the corner of my room typing this on my iPod and locked the door cause I think theirs a killer Down Stairs (I know there really isnt but my mind is screaming at me that there is something down stairs) why do I go insane at night??? Is there any way to make me sane at night? Cause I have gotten in alot of bad stuff at night. Like it has been like I have did stuff with random guys and i wasnt even thinking! (not had sex but like close to it stuff.) but I'm afraid one night I'm gonna go to far. I'm not as bad tonight atleast.