Believe it or not anxiety can cause all that you have mentioned. Were you given any recommendation about how to manage your anxiety? Sounds like you have been cleared for anything physically wrong.
My GP gave me some Diazepam to take for a week but I still felt as bad once I'd finished the course. Last week, he prescribed venlafaxine but I haven't taken it yet as the side-effects sound like they'd make me feel worse! I was thinking of consulting a homeopathic psychiatrist for a more natural solution.
My GP has been my doctor all my life and he assured me he'd know if there was anything wrong. He even gave me a hug because he felt so sorry for me!
I definitely would recommend going the homeopathic route vs the traditional meds given for anxiety. Alot of them do have side effects that can cause more problems.
All the best.