Hi Katie
I'm sure if your parents do talk about costs that they don't mean to make you feel guilty, it sounds like you're probably feeling guilty all on your own
Do they fully understand your condition? Perhaps they could go with you to a therapy session to get an understanding of how much all this is upsetting you, or to a doctors visit with you to understand the severity of your condition. Often knowledge creates tolerance and understanding. Perhaps if they realised that their comments aggravated your anxiety or how the condition itself is quite scary and uncertain, they may change their approach. But remember, you are probably a little oversensitive too, and the bottom line is they love you and I am sure they are very concerned and feeling powerless to know how to help you.
Best wishes
Deb