Capital Gains Blues

I recently got first-hand experience with the dreadful capital gains tax blues.  I owned a second business for ten years and recently sold it in order to spend more time in real estate.  I had heard of capital gains taxes, but I had never understood how painful it could be.  When we filed our taxes this year, Uncle Sam made sure he got a big bite out of our profit.  I still have difficulty understanding the concept of these taxes.  I worked hard to build my business over the course of the ten years we were open.  In the beginning I saw little to no profit and even found myself dipping into my own pocket to keep the business running.  Once we were established, I still felt that the time and effort I put into my business was not reaping the kind of rewards I had hoped.  However, I felt that once I was able to sell I would finally see the hard work pay off.  Now don't get me wrong, I'm not complaining about the money we made.  However, it seems that I got a double whammy on my taxes.  I had to pay somewhere in the neighborhood of about 20% (give or take) and then the rest was added to my income and then I had to pay more income tax.  This was a frustrating situation for me, but I feel as though it has helped me in my current business.  Hopefully, I will be more understanding of my clients who are investors and I will be able to relate to how they feel.  I would also like to lean more about these tax laws in order to help my clients who find themselves in the same situation.  If anyone can share your knowledge in this area, I am all ears!