Dented MacBook Pro. Won't boot.

Somehow my 13inch MacBook Pro was dented in on the bottom on the left side. It was working perfectly fine. I plugged it in & went to sleep. Hours later I went to use it, opened it up & it was off. I hit the power button & it took longer than usual to boot up, but it did & was again, working perfectly fine. Then I was using it for about 15-20 minutes when I turn it on my lap to show my friend across from me something on the screen, the screen froze & turned into a bunch of colored lines all across the screen. I turned it off & back on again and it was working again for about 10 minutes when I was editing a picture & it did the thing with the lines again but before the screen did that I saw a strange box pop up saying to restart or something, I didn't get a good look before the screen went out. I turned it off and now when I try to turn it on it freezes on the apple screen. Or it will power on, get to the apple screen and shut off. A couple times it won't power up at all but will make this creepy low beeping noise until I hold the power button in. I just don't know what to do now! I don't understand why it was working perfectly fine & now won't work at all! Any advice???

I agree with ThuyNga. It seems you damaged the MacBook when it was dented. There may be a damaged or loose cable. The hard drive may have been damaged. A cooling fan no longer cooling. Who knows. Bottom line... "something" is broken.