This is a painful situation. It calls for some careful detective work. It’s possible that the time has come for you to part. On the other hand, your perception may just be temporarily clouded by sexual habituation, and the lasting ill will it can engender.
Find out by devoting yourself to the careful nurturing of your partner for a sustained period. Incorporate more bonding behaviors into your interactions. If your partner is open to it, try the Exchanges from Cupid's Poisoned Arrow. Perception is surprisingly plastic, and can be improved using bonding behaviors and karezza.
Whatever the future holds, it is highly therapeutic to realize that the relationship craziness and chaos so many of us have endured had little to do with our mate’s hopeless flaws, our mental health, or our different planetary origins. Instead we innocently made ourselves nuts trying to please ourselves, or each other, in bed.
If the time comes to part, you will be better equipped to do it lovingly if you are seeing each other clearly, rather than through a veil of uneasy projections. Let bonding behaviors help with this process.