My Motorola Moto G (3rd Generation) won't turn on.

So: I have a Motorola Moto G (3rd Generation).
I updated it right away when Marshallow rolled out. It ran good after the update although it lagged a little bit, but it was fine. It went perfectly for a few days. Then I went traveling and I kept the phone right next to me. I started feeling a vibration. So I checked it out and following happened: I guess it suddenly went off (which it also did after the update, but it went on right away) and then it turns on, but not fully. As in it showed me the Motorola Logo, and Powered by Android and then it went off and it does this repeating. I am able to access this thing by pressing the Volumes buttons at the same time which allows me to recover etc. I tried recovering but it wouldn't allow me although I passed the "dead robot" it would show me the Motorola logo and go off and on.. I thought it was because of the battery but then my phone starting heating so I turned it off.

And I don't know if this helps but I set my phone in a way that the screen would sleep every 15 seconds. And I counted that it exactly goes off and on in the exact 15 seconds.

Hope you guys can help!