Well, I have already admitted that I have self-esteem issues that I'm working on. I think I've made some good progress, and I'm feeling happier. I will say that after I talked to the others, they admitted that they were all terrified that they would hurt me. They all knew that they were okay with being polyamorous, but they were so afraid that I wasn't sure of myself that when I got uncomfortable they just froze up.
And I got some good advice on this forum which helped us all immensely. Communication between the four of us is much, much better now. We've hammered out some rules and made a few more mistakes. A wonderful side effect is that communication with my husband has improved greatly. I think we've had more effective communication in the last two weeks than we've had in the last two years.
Please don't suffer pain or anger on my behalf. I was hurting, but communication resolved the situation, and my partners have all made a huge effort to reassure me of their love. All relationships have some hiccups.