Can a finance company share my medical info with other banks or financial institutions legally.

I have an auto loan through a finance company. Since I started doing buisness with Pioneer Credit of Bristol, TN I have been I have been hospitalized numerous times as I have beendiagnosed with esophigial varices and theis is a life threatening condition. They began giving me threatening phone calls while I was in the hospital recovering from major surgery saying that it would be to late for me to wait to make a payment. Which was a lie. Now since being home I have been trying to re-finance or trade my vehicle just so I can get out of doing buisness with them. They have taken it upon themselves to share with every auto dealer, bank, or financier that I have dealt with that I am about to die which is not true. I plan to send them a cease order to no longer share my medical info with anyone. What can I do to rid myself of these. I have a text message from one of the dealers that is how I found out what was going on.