My skin on the shaft of my penis is hurting if I move it. Too much sex?

Could be. I wold use a cool pack and rest the member for a while. If there is redness, bruising, or continued pain, you should see your pcp or urologist very soon.
Could be. Be careful if pain follows partner on top with you lying on your back. You can get minor fractures or splits in your penile rods if sex is too wild, this can lead to peyronie's disease. Otherwise pain could be from too much sex, in which case best to give it a pause until pain and discomfort has gone.