I think I just became a single mom?

My husband has apparently “had enough” of our fights/arguments. We have a 4 month old baby. Idk how to feel or what to do. I told him let’s talk it out or figure something out. But he said he doesn’t want to anymore. How can he throw away the 5 years together and a baby?!

Idk I’m literally shaking and sick to my stomach. Am I rly that dispensable