Droid A855 Problem! Please help!

Hello! I have a Droid A855, it has been owned by someone before me, I purchased it off of eBay in December and got it in January. Other than it's minor mishaps it's been a very good phone, until today. I've been watching YouTube on my phone today and the video started freaking out and YouTube became unresponsive but I could't close it out or go home or anything. So, I took the battery out and left it alone for a little while. I put the battery back in and the screen will light up and the menu buttons will also but that's all. My welcome screen does not come on, it will not boot up, the screen will only light up and if I leave it like that for a while it goes black and the menu buttons will light up. Please help! Is it a battery problem? Is it a phone problem? Please help me! Thank you!

 

Mike.757,
I also contemplated the fact that I might have over-charged it. I never let my phone completely die. I know that's bad for it, I will let it get down to 5% and then I immediately plug it in. Thank you for your help. Also, I have tried to plug my phone into the wall without a battery and it did the same exact thing as when the battery was in. I do believe it's time for a new phone. My current phone has always been buggy. Thank you for your help! If you have anymore suggestions, feel free to contact me!