Hey thomas,
I've followed your story for a while, and I get your frustration. I'm in my, er, early 50's, too. I started graduate school late in life. It took a while for me to get a job. It's not a great paying job, but the work is satisfying, and my boss is great!
I hope you'll keep working toward the kind of work you really want to do. You are talented and you do have a future. I think it's just a matter of finding a boss who recognizes that!
Hang in there!