What do you do when you're in love with someone who you may be entirely sexually incompatible with?
Since you say, "may be," that leads me to believe that this relationship is new, or that you are just beginning to question the compatibility. Human sexuality is fluid, and it can develop and change over time, but if you’re overwhelmingly lacking feelings of excitement, intimacy, and connection when having sex with your new beau, that might be unchangeable.
First, determine if you and your partner are sexually compatible for the relationship that you want. For example, a marriage will rarely be successful when one person constantly feels pressured or inadequate, and the other person isn’t satiated. Feelings of insecurity, resentment, and anger will overshadow all other relationship attributes. I’ve been on both sides of this coin, and it sucks either way. If you’re not sexually compatible and you both plan to be monogamous, please don’t get married. If you love each other, want to build a life, a family, and can have sex with other people, by all means, do that: you’re already communicating better than most couples that I know.