I just feel your pain. I would never want to go to that place again. But obviously you love him.
I am not a believer in lovers becoming friends. There is just so much raw emotion there. But none of us are the same or have the same experiences.
In my humble opinion - I think you should totally let go and move on. He has. He is with someone new. And you should not accept any crumbs from him. Although you are comfortable at his church and with his friends - I also think you should remove yourself from that group. Because clearly you are NOT comfortable there with J attending with him. That should be sending you a very loud message from him.
I remember when I was at that stage with ex and every little thing he did - I took as a sign that he wanted me back. And it was like ripping off a scab. I had begun healing but seeing him made me bleed all over again. It was only when I totally let go and stopped seeing him that the true healing began.
I am just sorry to see you hurting and having unreasonable expectations. If he wants to be with you - he will be.
I also remember what I told myself when I was in a similar situation. "If it's meant to be - it will all work out. If it doesn't - it wasn't"
Refocus. Build your life with others. Don't go to places you are likely to see him without her around. If he wants to see you - he has to be the one making that effort.
