But think Addaon also has a point. Yeah, the interview process can often be horrible. It can be demoralizing, especially after what the OP has gone through with their health (I have major health problems too, so can sympathize). For me at least, my solution was to treat a tough job search like a job. And in this way, you don't take all the rejection so personally (it's just apart of the interviewing).
Think this requires more context then what's possible in a post, but the OP may benefit from learning techniques for handling rejection? (I use them myself)