I made a huge mistake

He (34M) had a gf (30F) for years and since I started dating him I never felt jealous of her, only compersion. Or that's what I thought ..

What I was actually doing was idolizing her.. seeing her perfect-looking, loving, stable relationship she had with him as a shiny cool thing I would also get to have with him some day.

Boy was I wrong. As it turns out over the course of a few months, he doesn't feel romantic nor sexual attraction to me and apparently loves me "but more like as a friend"

Deescalation ensues.

We're gonna have to talk about the terms and conditions of our "relationship" in a few hours.

Any advice over important points to discuss and/or advice on how to emotionally recover (besides beating myself up for having been so naive) are appreciated.