IPhone 7 Plus Keeps Flashing Apple Logo Or Will Not Turn On After Charging Port Repair... PLS HELP

I really hope someone responds to this, I'm pretty hopeless. Here's what happened...

The charging port on my iPhone 7 Plus was loose so I ordered a new one from amazon to replace it. I have done many screen and battery repairs on iPhone 6, 6s, 7, 7 Plus, etc so I was confident I could do this. I found a video on YouTube on how to replace the charging port and I followed it step by step. Before I made any major changes, I disconnected the old charging port and connected the new one to make sure it worked. It worked perfectly. Then I proceeded to disassemble the phone.

I did not keep track of the screws like I should have. I got the logic board out and the old charging port out and put the new one in. I started putting everything back together and everything went smoothly besides the fact that I was putting screws in that fit, not necessarily the right ones because I had lost track. I got everything back together and tried turning it on and it would not turn on. I disconnected the battery and reconnected it and still nothing. At one point I got it to turn on but it wouldn't go past the apple logo, it would just keep flashing the apple logo. I plugged it into my Mac Book Pro via and apple lightning to usb cable and I held down the volume down button and power button and got to an iTunes screen with a website and a picture asking me to plug the phone into a computer. I unplugged my phone and plugged it back into the computer and still nothing, it just showed that page.

I left it sitting unplugged last night and this morning I tried turning it on via the power button (I was hoping for a miracle) and it showed the low battery symbol asking me to plug it in. I plugged it into an outlet and when I would click the power button it would show the low battery symbol but it had recognized that I had it plugged in because it wasn't telling me to plug it in anymore. I left it charging for about 15 minutes. When I went back to it and tried turning it on it showed nothing. A black screen.

Thats where I'm at now.

I don't know where I went wrong because I tested the charging port before installing it so it couldn't have been that. This is my only phone and my only way of communication besides my Mac Book Pro. I can't afford to buy a new phone and I know I could fix this I just come to dead ends everywhere on the internet.

If anyone has any tips or leads PLEASE reach out to me.