Sorry to read about your predicament. Hope you get this figured out!
I have no experience with this condition but my 2 cents is? You are asking on a site where with many Retirement Plans and Health Care Plans that are different and based on where you earn or have earned your rights for retirement and healthcare.
That being said, You want to contact the governing body of your actual retirement plan to see how its implemented in your region. Some regions your healthcare and retirement annuity come from totally different sources. So you need to find out your healthcare from the source that provides your medical for retirement.
Its not rocket science. Due yourself a BIG favor and go directly to the source that handles these issues for you! OR? Ask here and possibly get it all wrong. Generally speaking, going to your Local Teamsters office may source a number to call or contact info and that is about all they are worth!
Due to your medical situation you may find you have an early out? So many factor's need to be clarified but at least if you go direct to the horses mouth you will be better off!
Hope you get this solved quickly and to your satisfaction!