I'm going to yell back
With who? Why are you going to yell back at them?
Yell back to the person who's been mean to me
You shouldn't add fuel to a fire. Be a stronger person and just walk away.
I'm going to stop being manipulated by people I'm going to stop letting people get away with being mean to others. I don't care how big they are, I'm going to stand up to everyone.
While I do not understand the entire story, I think it is good that you would stand up to people that are mean, specially if they are doing it constantly. However, you shouldn't yell at them and be controlling of your tone and make sure you get your point across and you won't get that by yelling.