I am sorry your plant is not well. I don't want to answer incorrectly so I will simply suggest posting a picture might help others. Unfortunately once a tree has come to the point of looking bad it is possibly too late or will take time to get better.

What small plants are with the tree? If they are also dying it would point to the environment, not just the tree itself. Light, water, fertilizer, have any of them changed recently? Look for the upsetting factor.

As a side note to your other post, I have noticed as the year progresses that many of the Japanese Red Maples are slowly fading and more green is visible. Even the "Bloodgood" I saw at the store was visibly fading in redness. I know that doesn't help this plant but just for future reference.