Small horizontal cuts on penis shaft?

I have two small cuts. Not near the head. I think my skin was dry down there and I either masturbated or had sex while it was really dry. I take anti-estrogens and that can definitely cause dry skin. The cuts seem to heal or get a scab in a day. But as soon as a get an erection the scab splits open. Its not extremely painful but really annoying. Any idea what to do? The cuts are very small. One is about a quarter inch long and not deep at all you can hardly see it.