I'm a little late in reading your thread but wow- I should have sooner because I can totally relate to your experience. I wanted you to know you're not the only one. My H and I were involved in swinging also, and it's been a major downfall for us. He was very into it, and I endured because I didn't have the strength to set boundaries, and it took a huge toll on me personally and us as a couple. I finally started to realize what I had to do earlier this year when H couldn't say that our marriage was more important than swinging. (Even though we had a great sex life, he still "needed variety- it's nothing personal..." How much more personal can you get??) Anyways- I was crushed, and H still has a single male profile posted (married but looking). We have other issues too, but this was a huge deal for me.
I'm sorry you are hurting so bad, but I hope you know you're not alone.