Should I keep struggling with a slow business that was once successful or move on?
I say that because 21 years is a long time for any business--especially a retail business. I also have found that there are more opportunities in a down economy than in a booming one, and it would be worth your while to explore some options.
Owning your own business is still the best way I know to get wealthy, and I would do everything I could to find a new or better way to do business in your existing industry before starting over in a new and unknown one.
All the best. Brad Sugars.