I can only answer by sharing my own story. Hopefully you will glean something from it - and the conclusions I have come to. I was part of a polyfi triad that crashed and burned. I joined a married couple - the woman (I am female btw) and I had been friends since childhood. It all started off well enough, but then after becoming deeply emotionally involved with both she and her husband, and becoming fully integrated into their household, she changed her mind with no explanation. Very hurtful to me and to her husband. We tried to make it work, but I left 9 months after I arrived. 14 months and 2 marriage counselors later, they are separated and divorcing.
In the last 8 months I have reconnected with E, the husband. While we were both relieved to renew our relationship, people are not interchangeable and he has been totally grief stricken by the loss of his marriage and his relationship with his soon to be ex. I have had to emotionally come to terms with what I already logically understood: no matter how happy he may be to have me back in his life, the two relationships are separate, and I can't replace his loss. He has a right to sort through his emotions, and yes, at times his grief is all he can think about. He does not have the time and energy to devote to us. I have learned that that doesn't mean he doesn't appreciate me, but his pain regarding this other relationship has to be dealt with.
It has been 8 months for me and E is grieving a 15 year marriage and the mother of his children. It is getting better.
I have also been told things like, "I never believed my marriage would end," (it was ultimately his choice to leave an emotionally abusive situation), leaving me thinking, "well if it hadn't, we wouldn't be together." And yet I quickly came to realize that when he said such things, he wasn't seeing the connection between the two events; he was just in shock. So is B. When she says things like T was her soulmate, she really isn't thinking anything in regard to you. She is just expressing her loss.
Sounds like you are doing well. Just remember that whatever B says about T really has nothing to do with how she feels about you. You and T are not interchangeable.