LG G3 Issue, Please Help

[Chibu The Heart Emoji]

Okay, so I know this question has been all over already but I've done everything in those forums and nothing seemed to help. So I've had my LG G3 for a while and just a couple of months ago it gave out on me. I'm not sure what happened but it would just turn off on it's own, prior to this my phone has been heating up a lot and I figured that my battery was dying out. I've had occasions where I would wake up and my phone wasn't charged although it was plugged in and everything and the wire worked perfectly fine. I tried to replace the battery with a new one but it would cause a boot loop, and I tried my friend's G3 battery and it didn't work either, it would immediately turn off. The only time I can get it to work for a few minutes is with my battery but it would give out after a few minutes.

I have an At&t D850 Running 6.0.1 MM. I've reset it multiple times, figured it might be a logic board issue but I'm not sure. Please help.