problem! I am getting an problem since two years?

At first i was not using any medicine and i was able to get my , since two years i am taking pills such as canova, cupid 50 and so on. They were working quite good. Now i can see on taking the pills i can have for hardly 5 minutes, when i rest i can once again have for another 5 minutes. iam only 28yrs i have consulted many doctors, is my problem treatable? what should i do plz help.