I am going to yell in frustration
What are you so frustrated about?
I need to blow off some steam.
As long as you are not doing anything to anyone, yelling to blow off steam is fine. It is better to yell than to hurt yourself or someone else.
I can't take it anymore.
It's good to have a healthy outlet to blow of steam.  If yelling helps you should do it. It sounds like whatever is bothering you is really bad so you might want to consider finding a therapist to talk to as well.