Is it possible for this non-compete contract to hold up in court?

One year ago, I was forced to sign a non compete contract in order to keep my employment with a subcontractor for a water treatment company. This subcontracting company does the plumbing and installation for the units the water treatment company sells. Earlier this year, the owner of the water treatment company fired the subcontractor for misuse of company funds, among other things. The subcontractor then blamed me for their getting fired and therefore fired me The owner of the water treatment company offered me employment and I took it. Now, the subcontractor is threatening to use the non compete against me and the water treatment business. I do not understand how this can be legal; forcing me out of the only trade I know (plumbing) for a year. I cannot feed my family or pay the bills without this trade nor can I pick up and move across state lines.