What if I'm pissed at my boyfriend for being clumsy?
Are you joking? Why would you be upset at him for that?
I tell you one thing he's never going to play guitar again.
That is not nice for you to do. You should accept your partner's faults. You should not be upset at him for something he can't really control.
Don't tell me what to do with my boyfriend.
I am just warning you that you could damage your relationship if you don't accept your boyfriend's clumsiness. Clumsiness is not something cannot change.