Depending on what is in your condominium rules, it is possible to put a lien on your property if you don't pay assessments. The condo law says that decisions of the assembly re fees and assessments are binding on all owners.
Given your health situation, I wouldn't think they would take action against you if you sent a message explaining why payment will be late.
If you are determined not to pay, then get a lawyer who knows condo law and have him go over the record. Condos are not always careful validating proxies, following the law with respect to notice of meeting, etc, etc. Also have him look at the condo rules. You may find more than enough to invalidate the vote on this matter. Don't just get any lawyer, get one who really knows condo law. Fabio is one, there aren't many others to choose from in the DR.