Are the symptoms described related to Bulimia?

I am a 15 year-old female. I've had bulimia for a little more than eighteen months. I was recently in residential treatment, where I was symptom-free for about a month. Unfortunately, Monday was my first night back home and I gave in to binge-eating and purging. I have been symptom-free since, but I have developed aches in my chest, belly, and abdomen. The chest pains worsen on inhaling. It's definitely bearable, but it's persistent and it's making me very anxious. Does anyone have any possible explanations for this?
I am also experiencing a lot of dizziness on standing. I know that this happens because of orthostasis and I've been drinking three 16-oz glasses of water a day along with 1-2 bottles of Gatorade a day since the incident, but it does not appear to have improved. Is there anything else I can do?
Also, when I get dizzy, sounds seem to get blurred and muffled, as if I had cotton or water in my ears. This usually lasts for minute or two after the dizzy spell fades. What could it be?