Sometimes Non Responsive Touch Screen

Hello, so my screen on my iPhone 6 Plus sometimes will not work. My friend got this phone about a little over a year ago. It was perfectly good, she did although get the screen replaced a few times. But one day it dropped from a chair and fell on carpet. It was okay but they got the screen replaced AGAIN because it was cracked from the fall. But a few days later the screen completely stopped working from the bottom half. Anyways, she ended up getting a 7 Plus. She gave me the 6 Plus because she knew I had no phone. Well in about January of this year, we went to a guy who I thought knew what he was doing, he did seem a little sketchy though. For a while he was going on about how, when my friend would get it screen replaced by her brother, her brother didn't screw it right. The guy reset the phone completely. He decided to try and just put a different screen on it, it worked perfectly. The screen he put on already had a crack at the top and some weird white light at the top of the screen (no it isn't the flickering light I see people talk about). I was so excited I didn't even care. So we paid him and left. The phone was sitting by my bed for a good 4 weeks (I still made sure it worked and it did, during this time) Well after the 4 weeks I could use it. It was perfectly fine, basically brand new besides the screen. Then the next day, since I cant put it in my pocket since it'll bend. I have to devote a whole hand to holding the big phone lol. Well I was buying coffee and I had to get my money in my pocket, but both of my hands were full so I put my phone on the box I was holding, and it fell. First I was about to cry lol but I picked it up and it seemed fine. But after 2 hours or so I noticed the right side of the screen was popping out a little bit. I didn't really mind. The next night, I didnt use it for a while and when I went to use it, it didn't respond to my touch. I noticed now the other side of the phone, the screen was popping out. I dont know how it did this since it was lying on my bed. I started freaking out, doing everything to try to get to work, it did work if I pushed the screen in, but then wouldn't if I let go. Everyone I know thinks that since the crack (which is on the top part of the phone, like the very top, it makes like a little half circle around the camera and the speaker to the other side of the top part. Wish I could add a photo.) they think the crack is actually pushing the rest of the screen out. And it actually looks like it is because if I push the cracked part in, the rest of the screen goes in too. Its been going on for a while now and its getting worse. I taped the screen to keep it pushed in, and it looks like it's better but it still wont respond sometimes. Also if it stops working for a period of time I can double click the home button for a little bit and it works. Also if I lie it on its back for a little bit it works after a while. I'm here to ask if I should buy a new screen and see if it'll fix it. I'm seriously hoping it's not Touch Disease because he said it would be very expensive to fix, which I dont have the money to fix.