If you did it yourself, you wouldn't have to worry about someone else receiving ad revenue and royalties for the work *you* did… even after they've fired you. From what you've said, I don't think they treated you fairly at USgamer, why assume that working for someone else in the same way will be better? The only sure way to attain this ideal of a permanent position is to give it to yourself.

I don't think you're overreacting, you've been dumped and they're still trying to use you at the same time, so far as I can tell. Are you fired or not? If you're fired, you get your last pay and don't contribute anymore. If they really felt you were useless, they wouldn't be trying to squeeze extra work out of you, in whatever capacity.

Here's some useful links that would be helpful for self-employment:
http://www.w3schools.com/ – Anything about web development and design.
https://httpd.apache.org/ – Free and easy to use webserver software, works on most OSes.
https://www.google.com/adsense/ – Probably needs no introduction. Ad revenue, etc.
https://www.godaddy.com/ – There are other registrars, but this one is cheap and popular if you need one quickly.

Self-employment does take a lot of work, initially, but once you're set up, you're the one in control of your future, no one else hangs anything over your head or pulls the rug out from under you. You could be making royalties on the content you own, publish, and control, all while playing a video or board game for fun, or even if you're asleep or in the loo.

Sorry to be so intrusive, it's your life and I'm a person on the Internet, but I hate seeing people getting fucked over. But so long as we take it, employers will keep on taking more and more from us.