I brought an umbrella tree and the leaves have been going black then the whole branch falls off i have tried changing light food, and water methods and it is still loosing branches - there are these bits of fluff like cotton wool appearing and also the little white marks which dont seem to be moving although they may be really slow moving.

just want to know what they are and best way to get rid of the, to save whats left of the plant.

many thanks fo any info