bgb - so sorry this has become such a heart-breaking let down. Been there too, and have recently been trying to read and understand why I fall into the same trap. I found this site which has spelt it out .... It really made stop and think about what I wanted/didn't want from any (unlikely right now) future relationship. It may not be a great help to relieve the pain you're in right now, but looking to the future, I will be looking out for the 'red flags'.
12 Core Boundaries To Live By in Life, Dating, & Relationships | Baggage Reclaim by Natalie Lue
Hugs x