Reading your post, I'm "concerned" about your boss' concern. And that remark about tanking, *whew.* I went through stuff like that, and was perfectly healthy when I started working for the clowns who were my last employer (bitter and proud of it ;o). So I knew nothing about disability law and the protection they (purportedly) grant. Ultimately the company fired me, even though I could easily have worked at home (some did, but they were healthy) and I could have easily worked part-time (some did, but they were healthy). They immediately transferred another employee into my old position. Within a year I'd found a good lawyer and filed. The company is telling one lie on top of another, but their own documents are proving their dishonesty.
As someone who optimistically tends to assume almost all people are decent, some just need a bit of friendly enlightenment, here's what I've concluded: Many people are simply not educable. Especially those who place their self-interest above all others'.
If I were working now for an employer who made these snide remarks and expressed concern, (my opinion having been shaped by my experiences), I would document each remark, who said it to whom, and the time and place it was said. I would take the log I have right now to a very, very good employment / disability discrimination plaintiff's lawyer. And I would sit down and pay that lawyer for a few hours' time to begin documenting this nonsense. And do whatever the lawyer said I needed to do, be it lodge a complaint w/human resources, or let the lawyer right a letter to the boss, or whatever.
Seriously. I avoided confrontation the entire time I worked there, dragging myself around working much harder than I should have, and in the end my reward for soldiering on was my health and career both "tanking".
Having said all that, only you know your situation and you must listen to your own instincts. I wish you well!
i love the smell of doughnuts in the morning. it's the smell of... victory!