What do you think about me to tell my boss to fuck off?
Oh my! Why do you want to say that?
because he's a real asshole
Even though you might be frustrated with your boss, it is expected that you remain professional in the workplace. Swearing at your boss is not only rude and hurtful, but also can lead to significant repercussions such as losing your job and ruining your reputation. It can be difficult but try to find an employer that is a better fit for you and to leave your current job on as best a note as possible.
Fuck you. I'll say what I want.
I believe you asked for my opinion. It's pretty obnoxious to cuss at me, because you don't like it. People won't be willing to help you out if that's how you act.