So I started seeing my bf in May this year and it was great for about 2 and a half months. He had briefly told me about this girl (we'll call her Jessica) when we first started, I was fine okay with it because everytime he mentioned her, he kept saying they met a while back and nothing happened, they're just good friends. My definition of "a while back" is about 6-8 months ago but his is about 2 months ago. June came round and it's my bf's birthday and he tells me Jessica sent him a flirty comment and he tells her that his gf wouldn't appreciate that; this is when Jessica finds out about me. All this time I knew about Jessica but Jessica didn't even know my bf was dating let alone in a relationship with me. My bf is confused but lets it slide because she doesn't want to talk about it. July comes round and my bf reminds me that Jessica is coming to our town to see him and I'm surprised because I completely forgotten that he had briefly mentioned it the start of June and I thought they left it on a weird note, I tell him this but I'm like I trust you. I go on a trip out of town with my family and she visits on the days I'm out of town. He posts pictures and videos of them at an underground romantic italian restaurant that I had taken him on his birthday because he had never been there before, he had never posted me on his story, all of this made me upset. I tell him about my discomfort the next evening and I thought he invited his friend to hang out with them to ease my discomfort but this was later told to me to change up the environment for Jessica because my bf felt distant from her. Jessica leaves and I'm back from my trip. I have a dream where my bf is cheating on me with Jessica and there's a bouquet of sunflowers and roses in there. Ever since this dream, I have very bad discomfort with my bf and Jessica's friendship. I learn more and more about their relationship, how they were recent, nothing physical happened between them but they did have feelings for each other at one point. After a month and a half of breakdowns, I'm done, I feel like I've been piecing together a lot of things instead of just being told from the start the whole story about my bf and Jessica so after a lot of convincing, I tell my bf to go talk to her. And that's when he even finds out that she still had feelings for him and he ends their friendship. (He now understands my point of view on this and how it was an emotional affair, we both agree that it's a level of cheating)
Skip forward to November, I'm still hurt by my bf dismissing my feelings as just jealousy and not doing anything to ease my discomfort, he didn't think I should know that Jessica didn't know about me, he didn't do everything to not go to that italian restaurant, and some of the stuff he was saying didn't add up, so I told him I was going to talk to Jessica and he was supportive. I talked to Jessica and found out that even though they agreed to just be friends and nothing more in April, she still flirted with my bf here and there. Our conversation ended on a sour note and she had sent screenshots of the conversation to my bf (even though I had already sent him them). Jessica reaches out to my bf's best friend because they're friends and she tells her she doesn't want her name mentioned around my bf or me and that we're blocked.
I told my bf that I don't feel comfortable being friends with his best friend or being around her because she's friends with Jessica therefore her loyalties are with Jessica and I just want to remove every part of Jessica from me because a lot of things have been very triggering for me: the italian restaurant, the hotel she stayed, sunflowers, etc. My bf has told his best friend all about what's been going on and that easing my mind would ease his mind because he wants us all to comfortable and be able to hang out in group settings, but his best friend said that something similar has happened before with her friends and that cutting people off isn't the solution. Later on, Jessica removes his best friend from everything and his best friend tells him that she barely spoke to Jessica or reached out because Jessica's crazy. So I'm even more frustrated because she could've done something (cut off someone she doesn't care for) to ease her best friend and my discomfort but chose not to, even if it's a temporary relief.
We tried to break up and then he told me he was thinking of cutting off the friendship with his best friend for me but I told him I don't want him to do that nor do I want him to choose between me and her, I even said I'd take myself out of the equation because this is all too much. But he really wants to make it work. I've tried to set a boundary where I don't attend any event his best friend is at (his birthday, christmas parties etc) but at the same time I feel like I'm left out if all his friends are there with his best friend but not me. His best friend and his other friends have been friends for a long time so I don't think it's sustainable for me to be distant to her but still be friends with his friends. My bf is still confused on why I feel upset and how to go about handling these events even though I've voiced everything and repeated myself a dozen times. He really wants things to work but I feel like I've given him so many chances to him, he's weakened my trust for him so much that I have to set so many boundaries because I don't trust him to make me feel comfortable. How can we fix this?