Hi there. I don't know about breaking out in hives due to depression, but feeling sick is common . . . at least for me. When I was much younger than I am now (18 or so) and long, long before being diagnosed with MDD and GAD, I was nauseated every day and was prescribe Xanax. The stomach aches were nothnig more than a symptom of anxiety. Aches and pains are also very common among people with depression. I read somewhere that 40% of emergency room visits involving patients who believed they were having a heart attack turned out to suffering from symptoms of anxiety and panic (including shortness of breath, dizziness, seeing spots, sweating). I was one of those people about a year ago and the pain was very real. Of course, this doesn't mean anyone should dismiss physical symptoms as simply a product of anxiety, but only to point out that depression and anxiety effect us both mentally AND physically.
Take care of yourself.
Caiman