I am thinking that you should be able to buy COBRA insurance, resigning or not, and it will be the same policy you have, if you have health insurance policy through your employer. This makes a lot of sense for this year, especially so if all your copays, deductibles, and your out of pocket maximum have been reached. If you do not have insurance from your employer than this COBRA does not matter. After this year, you will need to see if it makes sense to pay the COBRA rate. It might. I think you can be on COBRA for 18 months max. But check this out as I am not an expert for sure on insurance, SSDisability, and employment laws.
Hugs,
Chrissy