Well this is just my experience, after my divorce and I started dating (and sleeping with) my current girlfriend all sorts of things changed for the better. Out of the blue people have come up to me and commented on how much better I look, and how happier I seem. And yes I'm sure part of it is putting my divorce behind me but I think a lot of it is having an actual sex life.

But with that said, if you do decide to have sex pick the right person. Along with sex comes all sorts of emotions, please be ready for them and being with the right person can make a huge difference.