HELP! Problems with my 8310

[SLHugheesX3]

Help!
I have a Blackberry Curve 8310, it was giving to me over the summer and up til' now it has been great. ABout two nights ago the full battery randomly drained itself and since then it wont keep a chrge. I charged it all night anda took it off in not even a hour the battery died. I then took out the battery and my sim card then put them back iin, the battery drained itself again. I put my sim card into another phone and I turned my blackberry on without it, the battery was full. I left it on for a couple hours not touching it the battery stayed charge. I put my sim card back in right when it turns on the yellow light starts flashing and it says the battery is drained. I tryed playing with the connection settings, my Wi Fi and Bluetooth are never on, I dont need them. I have no applications because I just use it to Text and Call. I dont know what else to do, Help please!!