It sounds as though you may well have a viable claim against your employer for retaliatory discharge/wrongful termination. You should consult with an employment attorney in your area.
You may have claim for wrongful discharge and should talk to local WC attorney asap. The problem is your empoloyer will claim they replaced you for legitimate business reasons and you may have to prove that your WC claim was their real reason, which can be hard to do.
You may also have an FMLA claim if your employer has more than 50 employees and you worked sufficient hours over the last year. FMLA gives you 12 weeks of job protection.
I am licensed to practice law only in Illinois. Any advice that I render is for general information purposes and does not create an attorney-client relationship. Also it is very important to keep in mind that all legal claims have statues of limitation to file that cannot be missed. A local attorney should be consulted to learn the time limits applicable to a particular claim.
FMLA may be a remedy if your employer is large enough and you have enough hours in past year. Otherwise, a WC Attorney may be able to investigate/file a case for retaliatory discharge.
We offer general concepts, but you should give ALL your facts to a licensed Attorney in your state before you RELY upon any legal advice.