Hello,
Firstly, it's important you know that fatigue does not necessarily you have AIDs. Fatigue can be associated with many conditions. It's good you used protective measures when having sex. But, I still advice you to avoid sex with sex workers, there are high chances they have HIV.
You could have excessive fatigue, maybe because you are anemic. That is a high possibility. Check your hemoglobin levels in blood first and check if you are anemic. And as you have also stated that you have a minor heart problem, I suggest you visit cardiologist to check if it hasn't aggravated over time. if there is increased pathology in heart, obviously the heart is not able to pump enough blood required for your body. In other terms less oxygen to tissues or less energy. Have a check on your heart first.
Thank you.