It could be so many things. And a lot of people have more than one illness. That really complicates things.
Along with bipolar, anxiety, and panic disorder, my pdoc thinks I may have ADD. However, the symptoms of bipolar and ADD overlap so much, it's hard to say. We're trying to treat the bipolar and see if the ADD symptoms lessen. If not, then we know we have something else to deal with.
That's why you really need to talk to a professional.