Why do I feel guilty for asserting the truth? For showing confidence and saying shit that didn't need to be said but was said anyways to expose perceived sideways behavior?

Asking because I got in a fight with my cousin. He broke something I let him borrow and he refused to recompensate me properly. I may have went too far, even if everything I said was true.

I'm typically a happy go lucky beta so I believed being an alpha for a change was supposed to feel good.