Damson tree canker?

El Evans

Hi, I have a shropshire St Julian Damson tree that I've had for about four years. It fruited really well the first two years, but last year although we had great blossom the fruit shrivelled up and died and the leaves were curled. And now this year we've had no blossom, just petrified dark brown buds and any leaf (very few formed) had died and dropped off, so that now in mid summer it looks completely bare. I've also noticed some recessed long wounds on some branches and peeling bark. It has a small hole at the base of the trunk near ground level and appears a little unsteady if the trunk is shaken. Is this canker? If so what can I do about it? I also have apple trees should i worry about them too?

Any help much appreciated. Thanks. El