Calling you selfish is a pretty clear sign the Deckman does not get it. Guilt never helps.

If you're a pro, I don't know that I could be of much help. You're in a job you don't enjoy and you'd have to re-kindle the joy you used to feel in order to want to keep performing.

If you're an amateur, the only way to get over fear of anything is by doing it. Prepare as best you can. Learn your material and be aware that you want people to enjoy your music. People want to enjoy your singing. It's not just you standing up in front of them, all alone. A performance is a team event--you're the leader. Your audience WANT to have a good time, they WANT you to succeed, and they don't expect you to be perfect.

The audience is your support, and you will feel wonderful when you have them with you. It sounds like you've been there before though, so you know. It also sounds like you're still performing even though it's "an ordeal". If you keep doing it, you'll get over the stage fright or decide you don't want to perform. If your "emotional setbacks" have caused you to have stage fright, there IS some connection. Relationships, even performer:audience ones are never only one person's responsibility. Trust them a little bit.