I believe this tree is called a bay ball. I bought it a couple months ago and was instructed to keep it moist and out of full sunlight. Since then it has been shedding and brown bumps have deleveoped on the underside of the leaves. Any idea on how to bring the tree back to health? Thanks!

Those little brown bumps are scale insects. The most successful way to get rid of them is to wipe them off with alcohol soaked cotton pads or tissues.

If you have lots though, that's going to be a big job. @WillC can suggest an assault on a bigger infestation.