Very upset

I have a 16 month boy who dropped his milk because he did not want his bottle. All of a sudden, I took the bottle from him and he cried. I then had a strong urge to slap him (I would never) and instead just screamed loudly "NO, all done...NO". I quickly got him milk after that but now I feel like a bad mom. Why did I have a strong urge to hit him and see him cry vulnerably. Inside my head I got feelings like it would feel good seeing him cry desperately. I am a very caring mom and feeling this way really is upsetting me. Any mom have stupid urges for no reason or when they are angry and lonely?