Phone turns on but wont work!

i was getting stuff from my locker and i always keep my phone on the top shelf where all my books are. I pulled out my English book and my phone fell on the floor, with that the backing and the battery came out, it also cracked my screen. It wouldn't turn on so i thought it just needed to be charged. Once i got home i put it on the charger, after that i saw the dot next to the SAMSUNG sign turn blue so i thought it was restarting. my bottem buttons had lit up but the actual phone had no picture accept in the middle of the phone there is a blue dot that is like 1 pixel. and at the bottom its like a green rectangle that gets brighter when i close the phone. I have no idea what is happening!! and this is my only phone and i cant get a new one, what should i do??