When i started taking AA's, my sex drive lowered within a week. And I am on a low dose, as well as being someone in a family where the males have higher-than-usual T-levels. But sexuality doesn't disappear, it just changes. I still have sexual thoughts and desires, they just aren't expressed the same way as I would've expressed them before as full male.
The best way I could describe it is that before, sex drive felt like pressure that needed releasing and was hard to control, now its a river the flows naturally, and when it rains (things getting hot and heavy) the river flows faster and higher until it becomes a white-water rapid and then slowly declines back to a gentle stream.
Very strange interpretation, I know xD But thats how it feels to me. Back then, whenever i would become sexually aroused, it was one of those things that needed to be resisted rather than something that comfortably be put-off for later. Now its just... different... its more about the experience and less about the release. Granted, I've only been on HRT for 18 days but my sex drive was one of the first things that changed drastically.