Try draining out the battery then do a full charge without playing with the phone.
Once fully charged unplug & turn off.
Pull battery for a full minute.
Turn on by holding power button and home button until you see the little DROID dude & release buttons.
Push volume up& down buttons at same time. A menu will come up.
Select "wipe cache" using volume buttons as up and down and the power button as the enter/select.
After wipe is complete the select "reboot phone".
This will reset your battery usage and all should go back to normal.
Sent from my Dx Humanoid