BLACKBERRY IS FROZEN!!!?

AHHHHH i am so pissed rite now like u have noooo idea. ok so ive had this blackberry for a year and it used to be my sisters. its like 3 yrs old id say, and i havent had much problems with it till today. IT JUST FROZE! someone was calling me and i couldnt answer, and i have a text and i cant open it, the buttons dont do anything the only thing that will move is the the black button and arrow. i cant do anything and im sooo pissed thisp hone is my alarm clock and i need it! i also was awaiting a text. :((( my mom is even more pissed cuz she just bought me a new ipod and she doesnt want to buy me a phone so of course she lectured me. its not my fault. I HAVE TO HAVE A PHONNNEEE. how can i fix this!!!!??plz help ill do anything! :(((