Gay man fell in love with a woman

I love him and I know that he loves me too, just not as much as her he was afraid of hurting her by needing something more than a heterosexual relationship some day, and he let her down.
I’ve always been an openly gay man, but I’ve fallen in love with my best friend who is a woman. We are about to move in together, so I’m now facing a huge dilemma and I’m not sure what I want. We.