anxiety. what fun? NOT

So Im driving down the road and my feet and hands start sweating, Im getting dizzy I feel like crying. I also feel as though I have to throw up and use the toilet. My head is spinning but not like I just got off a roller coaster but like I cant stop my brain from going on circles. My legs are weak and I feel as though if I stood up they would come out from under me. I know it isnt anything physical because just 3 months ago I had a CAT and MRI done which came back normal. So what the hell is this? Im prettty sure is an anxiety thing. That is really hard for me to say because it make me feel weak and stupid but when there isnt anything else you have to look at the obvious. I didnt sleep hardly a wink last night and I am worried about school. Not that I need to be Im doing great. I got a call today from the P.D officefor the job I had applied for. I have a interview Monday. What the hell do I have to be stressed about things are going well. Im focused on what I need to be doing, taking care of myself. So what gives? What gives is that I am scared to death. I am so scared of failing. Just writing this I am in tears. I know in my mind that I am capeable of so much but I dont know if I can do it. Im at the point now that I dont have a choice but I have to try because Im not able to stay where I am but it has me absolutely terrified. What if I dont get this job, what if I finish school and Im horrible at this, what if I fail misrabley with the LSAT's? yet I am so tired of setting myself up to fail just so I wont be disappointed when I do. It just occured to me that this isnt the first time I have done this. I have been scheduled before to take the written exam to work with the State Department as a foreign service officer and each time I didnt even crack a book to prepare. The last two times I signed up for it I didnt even make it to the exam because of some silly excuse that kept me from making it. Now I am actually on a path to make things different in my life and I believe that realization has finally hit me like a mac truck. I think also that she plays a role in this. She has always told me that I can do so much more and has always supported me with whatever I want to do . My issue is that I am so afraid I will let her down, and not just her but me, us. Even though there is no official us I still want to make a life that we can share in and I am so scared that I wont be able to. I feel like such a pathetic person. Saying that Im sure doesnt help anything but makes things worse. Where the hell did my backbone go, why cant I shake this, when does it stop?