I was so unhappy at Accenture for years, but I was always too scared to leave. Better the devil you know, right? Two months ago, I finally got the courage to move on when I lucked into a great offer, and I cannot tell you how much happier I am now.
If you are on the fence, please start looking. You might not find something right away, but you will eventually. And you will be so much happier for it. It changed my life.
Good luck, whatever you decide.