There are a few illnesses that can linger for years and have substantial effects on your hormonal levels.

I'd recommend, if your Dr hasn't done so already, that you have a blood test looking specifically for the Epstein/Bar virus. Its an indicator for mononucleosis which is frequently overlooked in adult women. My mother got it at 45(was still married, and still no idea how she contracted it either). It then led into CFS(Chronic Fatigue Syndrome) which literally lasted years and had a serious impact on her libido and energy levels in general.

Also check any medications you took to treat that particular illness-especially if you are still taking any. Many medications have a negative affect on libido. You may have to read alot of fine print to find ALL of the side effects, but its good to know what else your medication does.

Hope that helps.