Why won’t my iPhone 6 Plus turn on?

So I dropped my iPhone 6 Plus on the ground one day and I picked it up and it seemed fine their wasn’t any damage. but within a week the left side of the screen (where the battery is) started to pop out but my iPhone still worked and then I started to realize that the battery was draining faster than usual and I just thought I was using it more than usual but it turns out my iPhone was dying when it was at 80% battery and I did not take it into the store because I didn’t think it was a big deal. A few day after that it completely stopped working and now I can plug it into the wall using all Apple chargers and power adapters and it would turn to the Apple logo in a few seconds then turn off with a lightly lit black screen and it won’t go past that (and every time I unplug it it completely turns off again and won’t turn back on until it’s plugged back in). One time I got it to a screen that said I needed to restore it so I unplugged it and as usual, it turned off I tried plugging it into the computer and the computer didn’t recognize it as a device or anything nor did the phone turn on like when I plug it into the wall. I need help fixing this without purchasing a new iPhone and if possible, without buying a new battery. Can someone please help?