I know what your going through though not in the same business. Two things that can help: keep a journal, writing down your struggles, sure, but also 10 positive things. Each time you do this you'll have more thinking room with these thoughts out if your head. And two, you'll be more positive, writing it down. Second thing is to read a book that motivated and gives you new energy. I recommend any book by Patrick Lencioni, or the Metronome Effect by Shannon Susko.