Liz,
The symptoms you mention are very common when it comes to anxiety. I once became very worried about having an upcoming physical - and low and behold I began to have abdominal pain. The pain confirmed my worry and justified my anxiety - I was sure that I had cancer. The anxiety helped sustain the pain in my gut which fed my anxiety and on and on. I had a bunch of tests before a specialist decided that the abdominal discomfort was the result of colon spasms - and a symptom of the anxiety I felt.
Our bodies weren't meant to stay in a state of high arousal for long periods of time. The body's automatic reaction to perceived danger is swift and intense. Think about the last time something startled you - or you had a nightmare. For the digestion process to function, lot's of things have to work just so - with just the right mixture of the right chemicals. When you're in the midst of real or perceived danger, the importance of the digestion of your latest meal is preempted by the "fight or flight" response. Stay in this state for an extended period and you'll have an assorted array of symptoms and sensations - including fever like chills, gas, diarrhea, constipation, loss of appetite, GERD, insomnia, vision dysfunction, muscle tension head aches, heart palpitations, etc...the list is long.
That doesn't mean you can attribute every ache and pain to anxiety. Let your doctor help you sort that out. When your left arm goes numb accompanied by chest pain, get to a hospital - don't turn to CBT and try to talk yourself through it.
Welcome to the anxiety club. : )