and have quite a back catalog of games that I have never released out of fear they would get stolen.
Not legally relevant, but I read stuff like this, and I wonder what great songs or books or whatever exist but we'll never know about for reasons like this.
In the realm of legally relevant, your games are protected by copyright from the moment they're fixed in a tangible medium of expression. If you publish them, registering your copyrights is a good idea because, while not required for copyright protection, registration provides valuable benefits in the event of infringement.
but if anyone tried to steal my games and say it was there work then they could sue me right?
Anyone can sue anyone for anything. As a general rule, however, that doesn't happen, and if it does happen, you probably have ample evidence to prove that you created them and when. Right?
After all I have no way to actually prove the games are mine.
Why would you think that? You have no computer files with metadata? Notes? At a bare minimum, you have your testimony.
I have never trade marked or copyrighted anything.
These words are not properly used as verbs. As I mentioned above, from the moment you fixed these things in a tangible medium of expression, you owned copyrights. You don't have any trademark rights because you've never exploited your works in commerce. I assume what you really meant by this is that you've never registered any copyrights or trademarks.
Not sure if those are even methods you would use for video games.
Video games are audiovisual works protected by
section 102(a) of the Copyright Act (they also incorporate other types of works that are also protected).
I read somewhere you have to publish them with the library of congress but on there website they stated the game needs to be finished which had me scratching my head because some games are never finished considering I keep adding to them. So would I need to publish every DLC upgrade patch for the game as a stand alone item?
I can't address things you read or think you read, unless you provide links or citations. Generally speaking, when you register a copyright, you submit a copy of the work (but that isn't always required anymore). The submission copy is NOT published anywhere and is generally not available to the public (if it's even saved). What constitutes "finished" is impossible to determine in the abstract. However, there is no requirement in the Copyright Act that a work meet any sort of standard of "finished." As I mentioned above, if you want to publish something, you should register what you publish. If you later add to that, then you can register the additional content. You'll have to make a value judgment about whether the cost of registration is justified.