I don't know whether it would be considered abuse or not, but what matters is that it was traumatic for you. I can see how it would be.

I remember seeing my father drunk once. He'd been out with my mom & a very close family friend, my father's best friend. At some point in the evening he came home alone in a taxi & he was upset/angry. Not long afterwards my mom & the friend came home & I remember my mom saying that my dad had gotten jealous because she & friend were having too much fun & that he was an angry drunk. It was all very new to me & a little too adult for me at the time. Not nearly as traumatic as your experience, but I still remember it to this day very well.

Hopefully, you & your therapist can talk about this & figure out what meaning it has for you.