update! The issue seems to be Battleye related, because I tried turning it off and the server list got filled up instantly, and I can both host LAN and Internet. I can't play on a majority of servers yet (because no Battleye duh) BUT I will do some experimenting tomorrow!

yes, it's pretty much my only hope to still play MP again but I think it got dashed, I'm at my freaking wits end with this

Interestingly enough, even trying to host LAN games doesn't work since it shows me a sliver of a menu for a split second before kicking me out to the server browser.