As with most things in life, small iterative improvements are usually the most reliable path. You've already got contract work, so try to get more of that, maybe you can get a fulltime job with one of those clients, now you have a resume item, etc. It's the same for most everyone - we get a little experience, a bit of a resume, and one day we get another step on the ladder, and one day another.
Actually doing a whole degree program is just so much freakin' work and money for a single line on your resume that I can think of a lot of equally time consuming things that would have a better payoff. I've done night classes too and - whew. Never again.