!!! READ VERY IMPORTANT!!<-ANSWER
I created an account here just to tell you, and everyone lese since this is first response on a google search
I HAVE THE SOLUTION!! I struggled for a year, bought new routers but in the end, I found the answer and almost shot myself.
1. Go here What Is My IP Address? - IP Address Lookup, Internet Speed Test, IP Info, plus more
Trust me I'm goin somewhere with this.
2.copy and paste IP (don't care where) and :27015 at the end.
3.Then add connect before that. should look like this (connect ##.##.##.##:27015)
(please don't be retarded the # represent the numbers)
4.Give this code to somebody and have them put it in console ~
5.After that it'll show up and other people will join...ENJOY!!!
You still have to have your ports forwarded 27015 UDP/TCP. And thats it. The hell is over.
PLEASE LEAVE MESSAGE IF THIS HELPED/WORKED.