Advice needed...about lack of parity in emotional connection.

I could use some advice. Me: late forties, Transwoman primarily attracted to women until earlier this year. Began dating men this summer. Met a guy (30s) who is also in an ENM situation...and Identifies as poly. We both have one active other partner each. So this guy and I have amazing chemistry in nearly every dimension of our relationship...we have sort of solidified our relationship as something of substance that growing connection...with no changes to our ENM status at all. We both refer to each other as boyfriend girlfriend and have vowed to keep our ENM situation as unchanged.
Well my connection and attachment to him has grown to what I can only call "falling in love" with him. I have not expressly proclaimed it but I have almost slipped a few obvious times and we have talked about how we feel about one another as liking each other very very very much...but my heart breaks that I feel something more and worry that the intensity of this feeling will push him away. I. Already sense a subtle cooling in his language but I fear addressing it head on...like I should...will cause me to lose this amazing connection..

Ironically, as a monogamist I never crushed so hard on someone or experienced such unrequited love...

So what do you do when you feel more strongly attached than your partner does? I worry about how it can be toxic, that kind of unbalanced dynamic...I am trying to cool my own heels but It is crushing me.

Advice?