Yeah...I think you need to start respecting your own orientation and not place yourself in relationships that you know are impossible for you to maintain in the first place.
I'm not criticizing: I'm at the tail-end of going through this myself. I knew deep-down when I married my soon-to-be ex the following:
1. Even though it was only supposed to be a "marriage on paper," he would eventually take liberties, grow possessive and twist it into something more traditional.
2. It was unrealistic after my awakening to expect myself to go back to sleep and somehow will the truth away...un-shoot the gun, so-to-speak. I would eventually recognize surfacing needs and be stiffed and miserable or have no choice but to cheat and/or leave. It would become a bone of contention if I didn't fight for myself or end it then.
I chose unwisely.
You have entered a situation where you are now asking a mono to give up his sexual orientation so you can meet yours. You knew what your limitations were and still agreed to the current terms of the relationship with the mono. You need to be prepared to respect his limitations and either suck it up and go hungry or leave before the bitterness poisons you both.
I wish you the best. This is tricky.
Lots of love and strength...
"Although the most acute judges of the witches and even the witches themselves, were convinced of the guilt of witchery, the guilt nevertheless was non-existent. It is thus with all guilt."
How can you claim to love someone with all your heart if you can't stand to let them love with all of theirs?