Hello Sun-no-Shine: I'm so sorry to read of your struggles. Having had 1 bout with cancer myself, I have some idea of what that is about, although it sounds as though you've had a rougher time than I did.
I sometimes wonder about all of these mental health diagnoses patients get from their pdocs. Although I've been in-&-out of treatment for quite a few years now, none of the professionals I've ever seen has ever given me any kind of diagnosis. They just open the medicine cabinet, so to speak, & say: "Which pill do you want?" Sometimes I feel kind-of cheated by this... like if they would give me some labels, somehow I'd be doing better. But then, at other times, I think perhaps it's just better to not be told I have this diagnosis or that one. From what you wrote, it sounds as though you'd have done better if your pdoc had just kept her / his "obsessive behavior" observation to her / himself.
Personally, at this point in my life, I just keep to myself. No good has ever resulted from me having contact with the outside world. I am married. But, otherwise, I have no family & no friends by choice. I don't recommend this lifestyle. But it is what I have come to & it works for me. I don't believe there is a plan for me. There's only what I've decided to do (or, rather, not do) with my life, based on all of the not-so-great experiences I've had in the past.
It is very hard to be constantly confronted with other people's negativity, and even more so when you're struggling both physically & emotionally. I send warm thoughts your way.