When you say dwarf, do you mean a full size tree but on pixy rootstock? Do you have it in a pot or is it in the ground? It could be that the late frosts have killed off the blossom. No bees to pollinate so the fruits haven't set. Lack of water as we have had a very little rainfall. All this things could be a possibility. The sticky substance on the twigs could be bacterial canker which would be close of play for your tree I'm afraid.

Need a photograph showing sticky stuff on affected twigs, and the dying leaves really. Any insects on the backs of the leaves, or anywhere at all?

Thanks to jimmy and bamboo for your replies,after checking the tree again I think the problem is Aphids,I have checked elsewhere about Aphids and the description of the problems they cause sounds exactly like the problem Ive got.