I've been there, sort of. My ex-husband left less than a month after my mom (who was my best friend) passed away. He moved in with a previous girlfriend. I didn't know her then, but she was a former member of a theater troupe I joined shortly after he left. About a month after I joined, she came back, primarily to announce that she was the one now living with my husband (it was before the divorce was final). Now I had to deal with her being part of my new, very small and close-knit circle of friends.
I felt doubly devastated...not only was the hurt of being left still raw (and the pain of losing my mother), but the new girl had intruded into the safe place I had found while trying to heal. I also felt a bit betrayed by our director, who knew the entire story and allowed the girl to rejoin.
I ended up distancing myself from the group. I kept close ties to a couple of members that had nothing to do with the situation, but I moved everyone else to arm's length. I didn't burn bridges, and I remained socially polite.
As I suspected, ex-husband and new girl got married about six months after the divorce was final. Two years later, they got divorced in what I understand was a hellacious breakup. Both are still muddling along in dead-end careers and refusing to grow up.
Meanwhile, I stepped back and, after allowing myself to grieve for awhile, starting working on myself. Like you, I had a terrible time with being alone, tons of insecurity and worry, and a lot of self-doubts. As I worked on healing, I also worked on those issues. I still have to remind myself to trust my own instincts, but I'm doing so much better in all those areas. I've also built a successful career in a field I adore (writing). I travel the world full-time. I've rebuilt my relationship with my father (we had a major falling out when I was in my teens, and had barely spoken in years, now we actually travel together and are quite close). I'm doing extremely well now.
As I've grown and matured, I've come to realize how horribly wrong for me my ex truly was. I'm not going to say he's a bad person, just very, very bad for me. I'm still waiting for my soul mate, but I truly believe that when I find him, he'll be the right person for the me that I now am, rather than the insecure person I was then. I don't think I could have developed in this direction while I was with the ex.
I feel for you, OP. This sort of situation sucks, and I'm glad that you're able to recognize that and be kind to yourself. You did nothing wrong. Maybe your ex and your BF did, maybe they didn't. I don't know them, so I can't judge. But the net result is that you got hurt very, very badly. My advice is to distance yourself FOR NOW, in a way that doesn't burn bridges. Maybe you'll want to pursue friendship with one or both later, maybe you won't. Right now you're not clear-headed enough to make that determination.
Give yourself the time and distance to grieve both relationships and, when you feel ready, begin to work on healing. You will be stronger for this in the long run, I promise. In the meantime, take it one day at a time. If that feels like too much, take it one hour or even one minute at a time (I did a whole lot of that!). Just keep breathing and remember that every day you make it through makes things the tiniest bit easier.




