I feel your pain!
I have a somewhat more positive outlook on things....if I may throw my 2 cents in......
I have been exactly where you were, was stuck in the right seat of a regional for close to 4000 hours. Upgraded finally, only to be bought out and essentially stapled to another list. I actually quit flying due to the fact that I thought I'd never "make it". Got too frustrated. Well, that was by far the biggest mistake I ever made! You can't get it out of your blood! Luckily, after a year of NOT flying at all....I applied and was hired at a "Legacy" carrier, luck was on my side. Of course I am on furlough now (my second one to be exact.) Furlough is by far the worst situation for a pilot in my opinion. Been out for over a year now. But looks like a recall is just around the corner and actually had an interview recently. It's all about highs and lows with this career.
My point:
I have been kicked in the head SEVERAL times in the last 12 years by this career and felt like I was severely "hosed" multiple times. AND it has always turned around for me and it WILL again. NEVER give up!! Try not to make career altering decisions based on negative emotions or feelings of frustration/burn-out. I focus on the positive things like the fact the avg. age of pilots on my seniority list is around the 58-59 range... and from what I hear most guys will only fly to 62.
Also, I talked to an FAA guy and he told me that the amount of Commercial Pilot licenses issued are WAY down. I'll NEVER say there will be a pilot shortage, but there seems to be an interesting trend on the horizon: the amount of retirements predicted in the not-so-distant-future is not proportional to the people choosing to pursue this career.
Delta, Jetblue, and Airtran are all hiring. There is movement once again and I feel it will continue. It may take years rather than months but still.............Good luck!