Apple tree bark damage

The bark on the bottom 2 ft of my Apple tree is peeling off, there's baby woodlice & earwigs under the dead bark, the peeling bark does appear to be moving up the tree too.  Last yr my dad ' kindly' strimmed around the base, something I never do, and perhaps he damaged it?  The base is quite unstable too, my daughter used to climb on it but I stopped her last yr as you can push the tree, its only around 3m high, its still flowering and seems healthy apart from the bottom 2 ft! I really don't want to lose it, has anyone any advice for me???

It sounds as though the strimming did damage the bark. The real issue is whether the damage runs all the way round - if so, I'm afraid that the tree will not recover. The instability also points the same way, but also suggests that the tree may have already had a problem before the strimming.

If the bark is gone all around the tree, I'm afraid there's no way of saving it.

Thank you. I had a closer look last night and it does appear to have gone all the way round   Well I suppose all I can hope for is a final crop of apples.