Hacker15E has very good points-seniority means everything!
A friend of mine from college days was in a similar situation. He stayed 20 because he enjoyed his assignments and was lucky enough to fly most of his career. When he retired, he wasn't able to land a job with the majors mainly because of his low hours. As you know, the major airlines don't cut you any slack like they used to just because you have mil time. You can thank the flowery PC world of HR. I digress. Anyway, he got a job flying for a small corporate gig and in less than 2 years, he got on with a major.
The point is, the airlines still like mil time and if you keep plugging away (and you're not a complete dork), you will land a job at a major carrier. Don't give up and keep the faith!