try not to concentrate on your cock. Divide your awareness onto all parts of your body and hers, and when you breathe imagine the sexual energy building up in your genitals spreading all over your body. Imagine a circle of energy when you are kissing her going from your mouth through her body and back into you via your genitals and back through your mouth and into hers again. This method takes the burden off your cock and when you do come it'll be a full body orgasm.