LG G3: Keeps restarting (SOLVED)

image source: cnet

I have had the phone for just over a year and my experience with it had been bittersweet.
Initially, I had nothing bad to say about it, however things turned nasty passed the half year mark.

These are the problems that I have experienced:

1. Overheating..to the point that I cant even touch the bloody thing. This was fixed by the 5.0 update
2. Stock keyboard is slow as!! So I opted for another keyboard app
3. Stock UI is really laggy.

These are minor and are manageable issues. 

However 1 year on, a major issue I was starting to have was the:

1. Random restarts
2. screen brightness flickers

The phone went on a restart loop for about 2 hours. I tried every advice I can find on the Internet but nothing was working... 

Solution

I had the assumption that it could be the battery. Luckily I had one extra legit battery. I replaced what I had on and charged to max. Voila!!!It fixed the damn prob. it's been 36 hours now and I had no more screen flickering and random restarts. *fingers crossed* that its going to behave itself.