Right now it seems to me you're staying with your wife because you don't want to be alone. That doesn't sound that good to me. Doesn't sound very respectful of her either that you'd leave her in a heartbeat to run away with Bree but want to hold on to her if she's the only thing you have.
I think it might be best for you to just break things off even if it means being alone afterwards. Then you can rebuild yourself, decide what exactly you want, and work from there.
Or you could decide to stay, but then you'd have to be really into it. And I don't think you are. It doesn't sound like it's working out for you. I realise I could be very wrong but that's the way it looks to me right now.
I wish you the best, but I think you really need to figure things out for yourself here. And make decisions you can control. You can't control other people, you can only control yourself. Right now you're resenting these women for trying to do what they feel is best for themselves, but you need to start doing the same too, in my opinion.
Me: 31F, straight
Seamus: My husband, 32M, straight
Dragon: My boyfriend, 29M, pansexual, married to Fox
Fox: My boyfriend, 29M, homoflexible, married to Dragon