This is indeed a touchy subject, but I find that a lot of significant others also have their own health issues and aren’t perfectly healthy. My Crohn’s Disease is mostly under control, and my biggest health issue at the moment is not my IBD but my IAD (inflammatory airway disease), which has been producing long, debilitating bursts of coughing when I talk or exhale. My girlfriend has been plagued by migraine headaches and nausea recently. We took a trip to Lake George this summer, and although we had a blast together, one morning she woke up very sick which dashed our planned brunch that day. Anyway, we support each other as best we can, including dealing with our respective health issues and our relatives health issues. I feel she is always there when I need someone to talk to and I think or at least hope she feels the same way. I have supported her through some very tough times including a tragic accident that almost killed her sister and dashed our Christmas plans last year.
Ultimately in a relationship you have to have someone who is a supportive friend on the other side. I think it’s up to the OP and anyone else posting or curious about this issue to determine whether their existing relationship serves them well in that regard.
In my life I have had many relationships with different women. Always one at a time. Relationships that work the best I find are the ones where frank communication is easily had with the other person. Sometimes there are fights in a relationship and things get said that shouldn’t be said, but I don’t think those kinds of things are quite as important as the general “support vibe” you get from your significant other. If it’s not there then you need to re-evaluate things. If it is there, I don’t view one thoughtless comment as a relationship breaker, especially if it’s really unusual and isn’t normally something the SO would say.