Very sorry to hear about your health issues. What is it that you are trying to change on your tax returns as a result of becoming disabled?
For disabled adults:
There is an extra amount added to your standard deduction if you are legally blind. Your federal return does not provide any other credits or deductions for saying you are disabled, with one possible exception.
There is a credit for the Elderly and Disabled which is so small that very few people benefit from it—-it has not been updated/increased by Congress for decades.
ELDERLY OR DISABLED CREDIT https://www.irs.gov/help/ita/do-i-qualify-for-the-credit-for-the-elderly-or-disabled
There are some states that provide various credits to elderly/disabled folks, so watch for that when you prepare your state return. The states that I know of that have anything for elderly/disabled are AZ, CT, DE, IA, MO, ND, NJ, NY, VE. There may be others.
There is nothing special you need to do if you are disabled. You still report taxable income and pay taxes.
There is a small credit if you take early retirement and receive taxable disability pay, but it is income limited and not everyone qualifies.
https://www.irs.gov/credits-deductions/individuals/credit-for-the-elderly-or-the-disabled
Are you sure you need to amend?
How did you file your 2020 and 2021 returns, with Turbotax installed on your own computer or with Turbotax online? Here are the general instructions.