Tear on Penis tip won't heal

I'm 23 and live with my gf of three years. We have a very active sex life, or we did until this recurring injury. A while back we had sex without sufficient lube and a small tear appeared on the skin connecting the tip of the penis to the foreskin. I washed the area with safe soap, put antibiotic ointment on it, and left it alone. We didn't have sex for about a week waiting for it to heal. After a week it looked and felt much better, but after sex it was reopened and irritated. We've tried waiting a month and still after sex the wound re-opened.

I really don't know what to do. I know we have to go without sex for sometime, but will this ever fully heal? Anyone have any suggestions?