Good Morning Fred, 

Thank you for contacting the U of M Extension Service. 

I am not sure your tree has a designated "life".  How your tree has survived this long probably depends on how you've taken care of it. 

The drought we've had the past few years has been very hard on trees if they have not been watered regularly. This would be my first thought. It takes a long time for trees to react to stressors. 

Please click on the following link from the U of M Extension Yard and Garden website about growing stone fruit trees: https://extension.umn.edu/fruit/growing-stone-fruits-home-garden

If you scroll down there is information about problems and diseases with the trees.  You should inspect your tree, the leaves, branches and trunk for possible problems or insect infestation. Are there other symptoms on your tree? 

Please read through the above information and do a careful inspection of your tree. If you find more specific problems you can surely respond with another question about your tree. An antifungal may not be the answer. 

Good Luck!

Fred, 

You are welcome!