Hi James,
I can totally relate to where your at. I was a mess after the ENG too. To get over the first night following the test I first ate a good dinner which was high in protein. No sugar and no salt - that's important. Second, one hour before bed I took 2 mg of valium and then at bedtime another 2 mg. That did the trick. Everytrhing calmed down and I stopped freaking out...I even managed to sleep. I didn't truly get over it though for about 12 days. You will be OK.
Good luck....Scott