I'm not angry, I'm not an angry person, but I do sometimes like playing with the perception of anger, as in pretending that I'm more angry than I actually am, and sometimes it works quite well.
Don't wallow in brainstorming. Time spent fiddling with a business plan or filling up whiteboards with ideas is time that you could spend actually launching your business and seeing if the idea floats. Launching gives you real, solid feedback, instead of the imaginary 'what if' scenarios dreamed up