Jan, I am so sorry. My deepest sympathies go to you and your family and anyone else who loved him. It is so hard to lose a fish.
It is true that the fish (especially Bettas) bought at the LFS, including Petco and Petsmart and Walmart are generally older than those bought through private dealers. They dealers keep the fish and breed the ones that show promise or sell the ones they can privately before selling them off to the LFS and so they are kept until they don't feel they have a prayer to sell them themselves.
You can only do all you have done for them and provide them with a good and loving home for as long as you have them and care for them as much as your heart will let you. Then when they go you will know that you have given them a piece of you and they had a much better home than they would have had if you had not come into their life.
Bless you for caring and giving your Betta a place in your life and a place in your heart.
Rose
