I won't pretend to know a lot about D/s relationships, but even from the small bit I have learned, a Dom does not get to break boundaries and make unilateral decisions on such important information!
You are totally upset and well within your rights to be. Be upset, vent. Don't make a decision until you can think straight and whether because of alcohol or anger, that's not now. Whatever decision you come to, get out now or try and work it out, you will need to think straight. You will also need to tell him he screwed up, how badly and that whatever way this turns out, THAT he can't fix and can only understand and apologize and try to earn your trust back.
Me: Late 30s pansexual poly.
DH: My husband of 19 yrs and father of 3 teen girls.
DC: LDR of +4 year