Why did my screen go unresponsive after charging overnight?

[Ardian C]

I purchased an ATT Galaxy S7 in August 2016. I have changed the screen on it myself twice, once in November 2016 and the other last month February 2017. For a couple of weeks before the incident occured, I had noticed the phone would get exceedingly hot while charging. Fast forward to last week, I left my phone charging overnight (as i usually do) and the next morning the screen was unresponsive, no notifications could be heard either. The only thing visible was a constant green notification light. i tried all the different button combinations (soft reboot hard reboot etc.) from various online sources, but none of them worked - screen remained unresponsive and green light stayed on. Later that day, as a last resort, I decided to remove the back cover and disconnect / reconnect the battery. Even that did not work as I was still not able to get it to turn on, the only difference I noticed was that the green light came off and has not come back on since, not even while it's charging. Soon after, Icharged it for a good 10 mins and tried the same button combinations as before but nothing happened. I cant figure what else to do. I have insurance through att, but I want to exhaust all other possible fixes before I go that route because if i do file a claim, I will not have insurance for a year (due to filing a claim on the phone I had previously last year). Also I have a lot of pics and documents etc. on the device itself that I would like to keep. Are there any other fixes I could try? Thanks in advance.