I have a sapling almond tree which I grew from a seed nut brought from Spain about three years ago. It is about four foot tall and in a container. It seemed very happy for a while, but now it's getting very thin and 'woody' looking, particularly on the side not facing the sun (it's a walled garden facing east I'm afraid) and some of the leaves fall off easily. There is new growth at the bottom, but it just doesn't look happy. I put bubble wrap around around the container to keep the roots warm which seemed to help for a time, but wonder what I should do next? Help please!