I had protected sex and after sex the head of my penis swelled which has happened before but this time my foreskin has has swelled at the end of the head of the penis. It has some air trapped in it or what I really don't understand. It has formed a ring of sorts around the head. When I pull the skin back, the size of the swelling decreases but after sometime it again bubbles up. The swelling of the head has gone but this has not gone. I've used an ice pack, oil etc but nothing has worked.