Hi there!
I'm not a doctor, but I can share my own experiences in this regard.
I've heard of just about all of these symptoms occuring in people with anxiety in varying combinations and degrees, among many other things. Anxiety can do all kinds of crazy things to your body, even possibly be causing some of that doubt you're experiencing. I suffer from some of those very things, myself, and I was very skeptical of believing that anxiety can have such an effect for a long time. However, history and research has proved it to me--we know that the brain has an impact on our bodies simply because of the way we can control our limbs and such just by the impulse. The same applies here. If the brain perceives some sort of threat or stress, whether or not it's entirely rational or even completely conscious, chemicals will be released that causes bodily effects, sort of like how one gets really sore after a workout, or how an adrenaline rush works in times of stress, followed by fatigue--these all work more or less on the same principles, as far as I understand it. My therapist was just telling me last week about how anxiety has a more potent (and worse) effect on your body than any drug out there. Physical symptoms of anxiety are very much a reality.
I'm sorry to hear that you're dealing with these issues, and it's possible that you're actually experiencing more anxiety over trying to figure out where it's coming from. This is what a great number of us deal with very frequently.
Hope we can help you out and that you'll continue to post. Welcome to HW!
Risa