You should file for unemployment compensation. Additionally, many individuals are often misclassified as not eligible for overtime but in actuality they should have been paid overtime. What was your job title and duties? As for whether you have any other recourse, sometimes employers use not being a good fit as an excuse for an illegal termination. You should consider talking to an employment attorney.
If your employer's conduct violates the union contract, you will need to file a grievance. Normally, there is a very short time period to file a grievance, so you should contact your union rep and possibly an attorney immediately. If your hours were reduced for an illegal reason, for example race, sex, age, disability, or religion discrimination, you should contact an attorney.
Being required to clock out and continue working is a violation for non-managers/supervisors. If she would like to meet with me for a free 30 minute consultation to discuss what we can do about that, please have her contact me.