On ssdi & ssi. what would ins. cost if I get off ssi...?

I fought for the better part of 10 years and finally got my ssdi along with ssi about 6 years ago.. I know I cannot get off ssdi because I need several more surgeries and I live in a situation in which some days I can work part of day for 3 or 4 days in a row, then boom,  I have to take 5-7 off from chronic pain..  I keep trying to figure out what it would cost me if I were to get off ssi for just the insurance part of it as that's the main reason for me to be on the ssi...  I see so many abusing the system it makes me sick and I truly don't want to be a drain on the system even though I've paid in for it..  I also don't like going on discussion boards as I worry about having my IP traced and quite frankly being ratted out as if someone thinks I shouldn't be getting any benefits.. .
  Question.  If I were able to drop the ssi part and medicare what kind of premiums would I have to pay and what sort of deductible would be required?  
Thanks