How to show my wife that she isn't less worth through her illness?

For context my m35 wife f34 is suffering from a rare disease and is physically restricted. A few months ago she brought up to me that she doesn't feel worthy of me and told me she doesn't want to be a burden in my life. After that she lived a few weeks with her parents before I could convince her to come back home and that we should try counseling. We had the first few sessions but obviously something like that takes time. I want to ask if you have any idea how I could show her that my feelings for her didn't change in any way. Obviously I tell her that every day, iwrite her notes describing my love and I try to be the man a incredible blessing like her deserves but I am at the end of my ideas and it hurts me so much to see her feel this way.