It is a fallacy - a widespread fallacy, but a fallacy nonetheless - that an employee who is disabled or on medical leave has absolute protection from being fired. An employee who meets the legal definition of "disabled" cannot be fired BECAUSE THEY ARE DISABLED. However, that does not mean that they cannot be fired at all. It is likewise untrue that an employee on medical leave cannot be fired - if the employee is unable to return to work at the end of any Federally or state-mandated medical leave, they can legally be fired. In the absence of any Federally or state-mandated medical leave, the employee can be fired when they have exhausted any leave provided by the company.
In your case, I'm afraid the news is not particularly good. Because your condition is temporary, it does not fall under the ADA so you have no protection there. (In any case, the ADA only provides that you cannot be fired BECAUSE OF a disability - it does not state that you cannot be fired if you are unable to work.) And because your employer has less than 50 employees, you have no Federally mandated medical leave (FMLA) available to you. The only state mandated leave time your state provides does not apply in your situation.
That being the case, your employer is within their legal rights to terminate your employment because you were out on extended medical leave, if that is even the reason.
All of that aside, regardless of whether you are protected by the ADA, by FMLA, or state-provided medical leave, if your position is eliminated for legitimate business reasons that your employer can support, you have no protection whatsoever. ANY employee, regardless of medical leave, disability, workers comp claim, pregnancy, or any other type of leave, can be terminated if the employer can prove to any investigating agency that the position would have been the one/one of the ones eliminated regardless of whether the employee took leave or not. So if you were terminated because your position has been eliminated, that's legal too.