For you to enjoy sex, you should have adequate drive for sex.  There are so many  reasons so as to why some have high sex drive and some have low sex drive.

One of the reasons for low sex drive is stress. It is not easy to live stress free. Try and avoid stress in your life as much as possible. If you can not avoid , at least handle those stress carefully and adopt "take it easy" policy. It is not easy as I say- I know.

Stress reduces not only your sex drive but also your size. It is a proven fact that stress causes shrinkage of you tool. This adds fuel to your stress further.