It's in our DNA. As a species, procreating is our main goal. I sometimes like to joke to people who talk about "a higher purpose" because literally our DNA has coded us to have sex, make babies, rinse and repeat.
Upon sexual climax, the hormone endorphine is released into our body in the boatload to get us the "feel good" feeling. In fact, an orgasm is literally the body flooding itself with endorphine.
It's normal to love and crave for sex, it's a human thing. You can't fight with yout DNA.