Hi there ~
I understand your concerns. Firstly you do not seem to have any problem with your health, either sexual or physical. You might need to consult a psychiatrist
if there is any issue related to your mental health. I believe that you are having excessive thirst related to the sexual activity and this can be normal. Sexual activity may require a lot of water and energy (unto 400-500 Calories). I hope you consult a psychiatrist to find out the reason for your poor sexual energy and get on the path to recovery with appropriate medications. I hope this helps.
Take care and have a lovely day!