My story - anybody relate?

In September I had a serious surgery which required about 5 MRIs and alot of medications I don't know the name of. I had /cancer/peritonitis and am lucky to be alive. For the last month or two, I've noticed hair coming out on my comb and also in the shower drain...much more than should be there. The thinning happens to be in the back crown area and not much anywhere else that I notice. I haven't taken any new meds and no chemo or radiation. I am having a skin problem, which may or may not be scabies, which has been going on for over a year, so I don't think that's it. What can I do to stop this hair loss? Thanks to those who relate and/or reply.