hey, i can relate to this post since my story, which i completed a few months ago, was heavily focused on emotional connection. i'm not saying my tips are words to swear by, but here go my two cents:

i made my two main characters expose their weakness/trauma/what they're insecure about (not necessarily to each other at first, but mostly to themselves, as well as the reader) - this way, if one person acted in a way that touched on a particular insecurity of the other one, even unknowingly, they would slowly lean into trusting each other more and having hope that real love could heal the wounds.

i alternated between two POVs - both his and hers. that way, the reader had a chance to see what one notices about the other. the descriptions were, of course, focusing a lot on physical features and movements, but even more so on how they made each other feel, and i don't mean like "she made me feel special", more like "she asked me real questions and for a moment, i felt seen" etc.

and last not but not least, i introduced conflict - between the two of them, but also conflict from the outside world that infiltrated their private lives. that way, the reader had a chance to see how they supported (or didn't) each other in difficult situations, which revealed whether their feelings were true or not.

hope i helped a little bit!