Sim card or slot causing phone troubles

I downloaded "fortnite for android" apk off the internet onto my note 4 which is completely fake and I should have known better. And this is what I think started the problem. A day or two later I started seeing my phone start to slow down like crazy. It would take like 5 minutes just to Google something. After that my phone would shut down and restart or completely freeze and just not respond. I did multiple factory resets and it would work fine for an hour or two then go back to freezing and being broken. I put my sim card into a back up phone so I could figure out what was going on with my note 4.

When I started to play with my note 4 with the sim card out it was working completely fine. No slow downs and no freezing. So I thought it was fixed and put my sim card back into my note 4. Little while later I started to see the same problems again. Took my sim card out again and into my other phone. There are no problems with my s5 when I put the sim card in. I decide to use my note 4 for a couple weeks with out the sim card in there and it has been working great. I even took some canned air to the sim card slot and then cleaned the sim card. That didn't work either. I went to my phone company (metro pcs) to get a new sim card. He put the new sim card in and it just froze at the load screen. Took out the battery and tried again. It didn't even start up even after taking out the battery multiple times and trying hard resets. We took out the sim card and it started up perfectly and worked.

I have not replaced the sim card holder yet.

I've seen this same problem online but none of them got any answers.

If you could help me out that would be great.