I'm (F19) needing advice for my (M20) boyfriend

I need some advice because my boyfriend suddenly sulked (?) because he asked me if i'm having interacted with my boy classmates and I answered him honestly that I am interacting sometimes when it comes to grouping on school and I can't avoid having boy in my group because it was random. I explained all to him but he suddenly ignored me and now I don't know what to do and how to first move to him... He also seems angry (?) cause I told him it's not a really big deal... Now he's not chatting me and updating.. I need advice please..