Dealing with Blame from Family Members for Illnesses

I've had some friends doing this and it's really difficult to hear. I'm trying to remind myself they could never understand without experiencing it. The blood work from the ER being off in a way no behavior of mine could have ever explained didn't even help win me favor. I dont think they could be convinced. I've been trying hard to think of something I could say to gentle explain to them how important their perception of me is. I told them that, that I know they care and I care what they think of me. That helped some, but only in making sure the relationship didn't completely dissolve when they thought I was lazy and lacking will. But it didn't bring us closer together. And they aren't a bad person for not understanding it. Thats the worst part. I can't villanize someone who is just being human, who at their heart wants to see me excel by their own standards. My guess is they are very hard on themselves, not just me. Disability is isolating. And thats very difficult. I'm so sorry