First the numbers:12 million cancer survivors; at least 40 percent of whom have some sexual problem related to the disease. Sex after cancer doesn’t come easy, and sometimes doesn’t come at all. Rachel Zimmerman, blogger for WBUR’s CommonHealth, reports on the dimensions, causes and some possible remedies. Zimmerman talks with Dr. Sharon Bober, a clinical psychologist and director of the Dana-Farber Cancer Institute’s Sexual Health Program, who offers this advice: Face the Loss; Don’t Give Up; the Solution Is Not a 15-Minute Conversation. You can do this. Again.