I assume you are actually receiving workers' compensation benefits at this time. If not, if you could add the status of your comp claim to the question, that would help. The Texas Workers' Compensation Act states an employer cannot retaliate against a worker for filing a workers' comp claim. However, a company may fire an employee for actions such as violating company policy even after an on the job injury or can replace an employee who is out on comp if there is a business need. I recommend you contact an employment law attorney in your area who can discuss the facts of your case and determine whether the company acted appropriately or whether you may have a retaliation claim. There may also be Family Medical Leave Act issues to be considered and the attorney can discuss that with you as well.
If you are a Federal Employee who was injured on the job and are receiving compensation for lost wages and the weight of the medical evidence establishes that your restrictions are permanent and you will never be able to return to the job held at the time of the injury and your employer has no suitable light duty, termination may be appropriate. However, your compensation for lost wages will continue.
You can fight the termination through the MSPB or with a grievance through your union, but that is not always the wisest course of action. Sometimes it is better to allow the termination to go forward and to stay on OWCP time loss benefits.
If you have one or more dependents, the OWCP will pay 3/4 of the salary of the job held on the date of injury, the date disability began or the date of recurrence, whichever is greater. The compensation payments are tax free. Every March 1st CPIs are computed. There is no ceiling on the amount of time loss compensation you can receive and no time limit. Schedule awards can be paid in addition to time loss compensation but not concurrently. OWCP is not a retirement program and you are expected to return to work when you are able, but many injured Federal Workers receive time loss benefits indefinitely.
Every case where termination is involved is different, and I urge you to seek the help of a local attorney who is experienced in employment law.