What is wrong with my phone?

I have a Pantech pursuit and it works fine, a while back it would show pictures and it would shut down on me but it stopped doing it and it has been fine since the other day. My phone was frozen so i took the battery out and put it back in to turn on now it freezes on the loading to turn on screen. I wont turn on, i have tried charging it but it just freezes. How do i fix it?