Signing a no compete clause, as a Plumber, would basically be letting my boss know he has me by the balls,
You're a Plumber, with this clause (which I don't think is enforceable), if he fires you, or you move on,
You're going to get a job as what, a school teacher?
It's your living, it's what you do.
You're not going to compete in the only profession you have?
I wish and hope, you soon find the solution with your career, you've been frustrated for far too long.