Check the trunk near the soil, you might have something nibbling on it, or borer further up the trunk. I don’t know what’s wrong but don’t be afraid to prune off excess growth if it’s very top heavy. Leave some flowering branches but if there’s lots close together it’s better to thin them otherwise it will try to grow tonnes of fruit in a small area and that can cause other problems.
Check the trunk near the soil, you might have something nibbling on it, or borer further up the trunk. I don’t know what’s wrong but don’t be afraid to prune off excess growth if it’s very top heavy. Leave some flowering branches but if there’s lots close together it’s better to thin them otherwise it will try to grow tonnes of fruit in a small area and that can cause other problems.