M.P.
Look in the yellow pages of the phone book under Attorney-Labor. Make an appointment and go for an interview. There is frequently no charge for the first interview. Discuss your situation with him. If you don't think he's the right attorney for you, make an appointment with a different one.
If where you worked has a union, call the union office for advice on an attorney. If there is no union then perhaps you could call any union and ask them who handles their labor disputes.