Failed to bind to port

[QuanChuloo]

I'm trying to host a 1.12.2 server for me and my friend to play on, but I keep encountering this same error. Whenever I input my ip (not my public ip, my actual ip) into the server.properties file, it ALWAYS gives me the "Failed to bind to port" error no matter what port I've used (I've tried 3 times with 3 different ports), but whenever I leave the field blank, the server runs just fine, but only I can join (I can only use my public ip to join, hence why no one else can join. I am port forwarding correctly, and I've even tried to use a vpn to try a different ip, I don't know what else to do, and I'm getting really frustrated, any help is greatly appreciated.

Edited February 14, 2021 by QuanChuloo