iPhone 4 issues- please help!

I purchased a used iPhone 4 16GB (Version 7.1.2) last night- worked fine when I got it. Set up my service through StraightTalk and everything was working perfectly. Set the phone on the charger and went to bed. Woke up this morning, looked at my phone, sent a text, all good. A few minutes later I picked up the phone and the screen was black. I tried holding down the top button and the home button and the phone made a sound like it was taking a screenshot and the screen turned white. Plugged the phone into the charger, tried different combinations of pressing the top button, home button, etc, nothing happened and the screen remained white. Plugged it into the charger and left it there for a couple of hours. Came back and the screen was black. Tried holding/pressing home button and top buttons, etc, screen remained black. Took the phone off the charger and half an hour later the phone started vibrating on its own for several minutes and then stopped. I tried to plug it into iTunes for the first time and the phone started vibrating continuously and my computer made a noise like the phone was connecting and disconnecting its self over and over again, vibrating all the while and I received this message from iTunes "iTunes could not connect to this iPhone. An unknown error occurred (0xE8000065)." Since the phone's screen originally turned black, then white, then back to black I never saw the apple logo appear or anything else. I had an alarm set for 10:00 pm and the phone went off but the screen remained black. I have no idea what is wrong with this phone and I have no idea what to do. Nothing is appearing on the screen and I can't connect it to iTunes. The person I purchased the phone from said they never had any issues- probably definitely lying.

 

You're my hero. iTunes recognized the phone in recovery mode and is currently updating.

 

The problems continue...

So I was able to put my phone in recovery mode and get it working. Unfortunately, I am now putting it into recovery mode twice a day because it is still going to an unresponsive black screen every few hours. It will be working fine and then just stop. Any advice at this point?