What Causes Bruised And Swollen Penile Tip And Foreskin After Having Sex?

My girlfriend and I had sex yesterday and everything was fine.
About 2 hours afterwards she gave me a handjob for about an hour and a half.
4 hours afterwards i noticed that the tip of my penis down to about the middle/towards the bottom of my shaft is bruised and swollen. I am uncircumcised and my foreskin is very swollen.
Is this due to us not using lubrication and the friction caused by her stroking me so fast? Or...?