If you have disability insurance through your employer, you must check that policy immediately. Many provide that if the disability developed while you were still employed and you apply for benefits right away, you may still be covered. The window for application is often very short, so do not delay.
In addition, if you think your employer terminated you because it feared you were going to take a disability leave, or that you would return from your disability leave with impairments, you may have protections under the Family Medical Leave Act (FMLA), the Americans With Disabilities Act, the New York State Human Rights Law and/or the New York City Human Rights Law (all described above). You should promptly discuss this situation with an employment attorney, as some of these laws have short statutes of limitations (deadlines for commencing a claim).