Swelling in skin below penis bulb

Patient: I am 22 years of age. Four days back, while I was masturbating, I found that my foreskin slipped down to reveal the bulb of my penis for the first time. Since then, the foreskin did not slip upwards. Further, at the immediate next part of the bulb (moving upwards), I am having swelling of skin which is growing day by day. I am having problem in sitting, urinating and do my day to day activities. Please advice me what to do to reduce this swelling and get the foreskin back on the penis bulb.

Symptoms: Swelling, irritation in skin,