Hey there!
I'm in the middle of a "spell" of Grave's disease, which is autoimmune hyperthyroidism. It's normally under control, but it makes me feel absolutely nuts and quite ill occasionally. When my thyroid hormone levels are elevated, I have a heart rate of 100+ at rest, a pounding heartbeat, sweating, crazy diarrhea, weight loss, and I definitely become more anxious (which is probably a natural result of having such a high heart rate at rest).
I was diagnosed about six months ago and got my thyroid medication stabilized (I'm on Tapazole) but I think I need to increase it because I'm starting to feel crappy again (then again, I'm also in the middle of a 4,000-mile move across the country - doesn't help, but this is getting ridiculous). You might ask your doctor to try some atenolol or propanolol - these are beta blockers that can decrease your heart rate and blood pressure.
Some people have transient hyperthyroidism (Crying said she had it when she was pregnant, which is fairly common) and it will go away, but you should get a copy of your blood test results. Grave's disease will have a very distinct profile (low or undetectable TSH, elevated thyroid antibodies, elevated T4) and other types of hyperthyroidism can usually be distinguished with this blood work as well. They may want an ultrasound or I-131 uptake scan, though, which is the gold standard for diagnosis.
Best of luck!