Sorry to hear you're feeling that way. Please don't kill yourself though. You're only 40 and that's still plenty young enough for things to change in your life.
Never give up on applying for jobs. Someone will eventually hire you, you just have to look more and may even have to relocate to another state or town to find a job.
You can also see if you can get a student loan and go to college to pursue a high paying career. You're never to old to go to college.
Please don't give up. Something has got to change for you. I wish you the best.