The employee does not have to keep your job for an extended period of time. They've given you the 12 weeks FMLA and you've exhausted them. But you have another option. If at all possible, can you tell them you are ready to return to work with some accommodations? For example, can you work from home, or a flex schedule, etc? By law, employers must engage in an interactive dialogue with a disabled employee who asks for a reasonable accommodation. But you have to first ask in order to get the process going. I am including a link to my website re this issue. Time is of the essence. Get the process going asap. You may be able to return to work on a reasonable accommodation while you finish your treatments. Good luck!
This information should not be construed to be formal legal advice nor the formation of a lawyer/client relationship.
Typically, Short Term disability benefits are paid for a term of 6 months. After short term disability benefit, many employers provide their employees with Long Term Disability Coverage through a Long Term Disability Insurance Policy. If your employer provided such a policy you will want to make a claim prior to the exhaustion of your short term disability so that there is no gap in time where you do not have income coming. If you are unsure whether you are covered under a Long Term Disability Policy, call Human Resources at your former employer and find out. Also, ask for application paperwork if you are so that you can get the ball rolling immediately.
Should you not be covered by a LTD Policy, the other alternative is to file a Claim for Social Security Disability Benefits. You may want to start this process as quickly as possible because the government works very slow sometimes (as you could guess).