I have a really low sex drive and it's driving a wedge between me and her?

[Me]

i've been really sick lately (i had pancreatis infection and ulcer and almost needed surgery) and she knows this but she still wants to have sex she told me that when i feel ready to do things but then she got mad because i've been a lot less affectionate and haven't really felt like myself. even when i started feeling better she doesn't understand that it takes months to recover not to mention my meds might be killing my sex drive. maybe she just likes me because of the sex? how could i explain to her that it might take months before i start feeling like myself as in get my sex drive back and start being affectionate. i was in 24/7 intense stinging pain for a week and have organ damage i don't think she understands and it's going to take months to start feeling better.