If your mate believes it is, call your physician. You may feel embarrassed discussing sex, but this is too important a problem to let modesty stand in the way of a solution. Infidelity, or more likely fear of it, can present a problem. Exploring these fears with your mate is probably the best way to deal with them. If you admit that you are plagued by uncertainty and insecurity, you probably will receive the needed support and affection and can lay your doubts to rest.
Some cancer patients cite disfiguring treatment as a cause of sexual problems.
You need to deal not only with discomfort or disability but also with what this change in your body has done to your feelings about yourself. As awkward as it may seem, you need to find ways to communicate those feelings to your partner. An inability to express them may complicate an already difficult period. Each of us develops over the years an image in our mind about our body. We may not be completely satisfied with that image, but usually we are comfortable with it when with someone we love.