Open Relationship Turned Sour

My boyfriend and I have been together for nearly four years now. One year into the relationship we made the mutual decision to open it up sexually. This allowed us to have threesomes and occasionally have one on one sex with another partner. Everything was great, we communicated and never ran into any issues.

One year ago I had a surgery to repair a shoulder injury. As a result I wasn't able to workout and it affected me really bad mentally. I went into a depression and ended up losing about 30 pounds during my recovery period. This put a lot of strain on our relationship and my partner and I all but quit having sex. He told me at one point he was no longer attracted to me. This sent me spiraling even deeper into my depression.

Around the same time I met a friend online who had recently gone through a breakup. He was in a horrible place and we bonded platonically out of misery. We began to spend a lot of time together, nothing romantic. All the while my boyfriend would still go off and have his sexual one on one's with other partners. This was a few months into my recovery and I was starting to feel and look better and was back in the gym. Our sex life started to get back on track and I had formed a new meaningful friendship.

About 4 months into all of this, my new friend expressed interest in getting closer to our relationship wherever he fit in. I expressed the same interest and brought it up to my partner who was ok with it at the time. The three of us formed a friendship, although there was not a strong attraction between the two of them as there was with myself and the both of them. This went on for a few months without any hiccups. I spent the majority of the time with my partner, I would hangout one on one with my friend (nothing sexual still at this point), the three of us would hang out together, and my partner would still go off to have sex one on one with other people.

All that changed last week as we were out celebrating a birthday. Alcohol was involved and my partner asked me if I loved my new friend, to which I honestly responded yes. Now my partner has broken things off with me and says he is completely done. He doesn't want to be around me, much less my friend and says he feels betrayed by my emotional affair.

My justification to all this is that the idea that he can have sexual relations with a person and it not have any affect on our relationship, but I can't form a deep bond with somebody without it disrupting those feelings seems hypocritical.

I have no idea what to do and I'm at a point now where whatever move i make I'm hurting somebody. I can't imagine life without my partner, but at the same time my friend has been a really good friend to the both of us.

Please help.