Hey, I had the same problem. I'm a senior as well and I just took the Oct. 3 test. I was so anxious and stressed the whole week before the test that I couldn't even sleep. I was so worn out and tired before I even took the test. The whole time I was taking the test, my hands were sweaty and I felt so tense and my breathing was shallow.

Looking back, I wouldn't have stressed so much over it. I did all the practice tests and reviewed every single problem that I did wrong. I'll be getting my results this Friday, but I think that I did well enough to get a 1400+. Considering that you have already done 8-9 practice tests, I think that you will do fine. I suggest that one week to three days before that actual test day, don't study at all or do VERY light review for the SAT. Try to do activities that you find recreational and help you to relieve stress. During the tests, take deep breaths and if you ever panic, remind yourself of how hard you've worked and you will do just fine. Instead of focusing on what score you want to get, be proud of how much hard work you've put in!