I'm 18 months into early retirement after having been partners in a small business for 17 years. Here is what I can tell you, if you absolutely love what you do and your partner or partners are awesome, don't quit just find a way to scale back. You'll miss the sense of purpose and social interaction side if you just quit cold turkey. My situation was a cold turkey one, but it worked great for me because I was able to sell out to my other partners who thought the business was just a cash cow and ran itself. Well they found out the hard way it does not, I cashed out at the absolute top and it accelerated my retirement by 5 years, talk about a win win for me!
What you'll have to be able to accept if you do try to scale back is that the company will most likely not operate as efficiently and it will not be as profitable. Maybe you get lucky and hire a superstar or superstars and it actually does better, but small companies usually perform best when they people there running it day to day have a vested interest in accounting for every dollar spent and received. Basically just take a deep breath and its okay if all of these things happen, I for one would not trade the last 18 months for the world, and tomorrow I'm off on a 2 week sailing trip, life is good jump in : )