Cherry tree not thriving

My tree was planted when the house was built some 16 years ago. Since then, I have watched it grow and thrive. It had always flowered and fruited prolifically and needed little maintenance as it shaped itself beautifully with a lovely canopy that this dwarf tree seems to enjoy.
I have had no flowers at all this year, only strange little bracts where the flowers should be. Leaves are tiny or non existent. The trunk of the tree shows deep pitting for about 5 feet. Where it splits into 2 branches, one continues with this pitting for another few feet but the other is clear. There is also a small area where the bark seems to have become quite fibrous.
I am so worried as it is my pride and joy, having saved and fought for it amidst my husbands occasional ideas to redevelop the front of the house! Any advice appreciated
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I'd suspect part of your tree has died. It looks as though boring insects are eating away at the dead wood. I'd call in a tree surgeon to have a look at it.
Thank you Dave, yes it does look to be some kind of boring insect. Sadly, the worse part of the pitting is on the main trunk. I was a little flummoxed not to find anything on the internet about this outside of the USA.