Military flying is out, even the army only takes early 30's.

Federal LE is out, age 37 max no waivers.

I would find a comfortable place to wait things out, and build time on the side. If the industry looks better in the future, reconsider at that time. Indefinite flight instruction with no end in sight might be OK if you are 23, but probably not at age 40 unless you can really rake in the money (there are still some places you an do this if you bust your hump)

When hiring resumes assume that 1500 TT and 300+ ME will be the ticket initially. Those numbers may come down a bit as the applicant backlog gets used up, but there is a good possibility that federal law will require an ATP (1500 hours) in three years or so. I would plan on needing to get the ATP before you get an airline job.

Except for a few brief periods late (ie 2006-2007), regionals normally required 1500-2500 hours anyway. Nothing new there, just back to normal.