Funny thing about dreams, what they seem at the surface, aren't always what the subconscious is working through.

I once, had a dream, that stayed with me, when I was 3/4 years old. It was a knife floating through the air. Most of my life, I wondered about the meaning of that dream.

I was harboring anger. Knives represent unexpressed anger. I was angry about something, that happened to me, in that time frame. Clearly, too young to articulate that anger.

It was liberating, to realize, it symbolized anger and not homicidal tendencies.

Hope you can clarify your dream for yourself. You weren't actually cruel to your mom, in real life. You subconscious could have been grieving, et al.