i'm desperately in love with him

... and he knows it, and loves me too. we're open, but call each other husbands. he helped me realise i was trans. but he's "gay" - as in, only for men born with dicks... and it kills me that he's not into me /sexually/ because i have a vagina. it's been five years. recently he started crushing on a cis guy and told me and i told him how inadequate it made me feel and he insists it'll go nowhere but i'm terrified i'm not good enough for him because i'm not cis enough