Sounds like this is your problem. The interviewing is more of a sympton rather than a cause.

I'm not the US, but I find it hard to imagine it is much different in Chicago to where I am in Northern England - companies are dying to find good developers. Every company I've worked for, they always ask me "do you have any developer friends that would work here?". So why aren't they asking you to stay on as a perm employee once your contract is up? It sounds like you need to work on getting better at your job and delivering value to the companies that you work for.

If you don't make the football team - is it because you are bad at try-outs or are you just bad at football itself? (Sorry, brutally honest.)