Hello from JustAnswer.
The symptoms of feeling low, upset, hopeless, and worried are common symptoms of depression, and depression is common in people with bulimia. Some people have more rapid mood swings than others. The other issue, though, is whether the better moods are normal or elevated. Someone that swings from a normal, good mood to a depressed mood would have a type of depression. But if the better positive days include moods that are higher than normal, that would be worrisome for bipolar disease.
The outbursts and pushing people away can occur with either type of condition, so does not help to differentiate the conditions.
In either condition, though, significant symptoms would warrant being seen by your doctor for an assessment and consideration of medicines to help control symptoms.
Have you seen your doctor for any of these symptoms?
Are you taking any chronic medicines?