Well, i'm not gonna knock ya, or beat you up on your multi time. You said it yourself, the 121 guys are taking the jobs that were once being filled by even the low time pilots. As the market gets saturated the minimums will come up until the number of applicants decreases significantly. It all happened rather quickly, but things went from newly licensed pilots getting jobs out of college, to 10,000 hr pilots being put on the street, things are more competitive everywhere. More competitive to the guy with 300 hrs, and more competitive for the guy with 737,757,767 on his resume' .
Don't beat yourself up over it. A few years ago i sent my resume over to lakes. Didn't even get a phone call, instead was graced with a letter saying "please apply when you have more experience". No biggie, i wasn't expecting an offer anyway, and just continued instructing. By that fall, i'd found myself into a regional job, sitting right seat, and thinking "wow, don't know if i was really ready for this." By the time i got passed that, they had me thinking the same thing from the left seat.
Your time will come.