so I picked up my phone and it has a bunch of coloured bars down the side and I try to slide to unlock and it goes crazy and starts doing a bunch of random stuff. It has been acting up since I got it, it randomly freezes, the other day every time I tried to unlock it it would freeze for around 5 minutes. I dropped it a bunch of times but only once did the screen crack from dropping it. iTunes won't let me back it up because it's locked but I can't unlock it. Also I can't slide to power down. Any tips?