I don’t get it. You would appear to meet criteria for being hired as an FO at almost any regional if you went out and got current and maybe an instrument refresher. With 285 hours of prior 121 time you could upgrade in a year at some places. With signing bonus the first year and upgrade the second year you could likely make $120K or so in your first two years - not what you are making now but more than you’d get as a CFI - and be competitive for an ULCC in a couple of years.

Things have changed RADICALLY since you last flew 121.