I am so sorry that you feel bad about losing touch with your friend. This happens to everyone, unfortunately. You did so well, but time and distance have a tendency to blur relationships. I know you feel really sad about this, but just do what you can to continue the relationship as well as you can. If your friend feels the same, then you will get back in touch like you were. But don't be surprised if it is never again like it was. It happens. Just do the best you can. If you mean a lot to her, she will try harder too!
I'll be your best friend, Val!! I am old enough to be your mom, but I think you are the GREATEST!!