And wecome to HW as you can see we try to give a lot of support here in understanding this disorder and how to help with dealing with it and I think that debaser has given you some really good info on this and I'm glad to see that you are trying to get help with this from your doctor and you may try looking into CBT for way's to help you to relax and I will bump this up for you to look at.
welcome read up about panic attacks on the net
anxiety is often diagnosed by eliminating all other possible causes
bad reactions to antidepressants are common for anxiety sufferers, I hope you do better on the effexor
valium or ativan are always helpful and I would get back to work soon, also you should get out and exercise, even if its walking close to home
You might very well have hyperthyroidism - I was just diagnosed with this (Graves disease) and the symptoms were merciless! Even after two weeks of medication I still can't sleep, have hand tremors, a pounding pulse, and weight loss - these are classic signs of hyperthyroidism. It can really mess you up. If your thyroid test comes back negative, I suppose these symptoms could be chalked up to a bad bout of anxiety, but normally weight loss would only occur in that state if you are really restricting your eating. I'd be curious to see what the thyroid panel looks like. Has your doctor given you anything besides ativan?
If you do have hyperthyroidism, it's not the end of the world.