I am 42 years. I am unable to maintain erection continuously even for 10 seconds when I take pills like Tadalafil 20. This is the same case even when I do without having pills and of course since from my very first time of masturbation timings. I don't have any bad habits even smoking, etc. Nor had any significant medical case. But, I feel always tired of doing outside works but do very well my office paper works without any compromise. Recently I came to know my Sperm count was just 12 millions with half an amount of motility. Since I thought of doing some some exercises at Gym would increase my fitness and energy, I tried twice but immediately after a few seconds I got very tired. I have had no problem in my back bone. The only thing I would like to say that I suffer from is I suffer from breathing problem which makes me to breath always by opening the mouth for which I didn't take any test so far. Please suggest how can I maintain satisfactory erection in my sexual life.