I'm very sorry about your anxiety; I know how awful it is.

Everything you've said so far on this thread is consistent with Panic Disorder and/or OCD, and there is nothing to me to indicate Schizophrenia or any sort of loss of touch with reality. Moreover, you haven't described any symptom that is characteristic of a manic episode (such as feelings of self-grandiosity, impulsive behavior, going on spending binges, staying awake for days on end, etc.). The racing thoughts and fears of going crazy are common, standard symptoms of anxiety (which doesn't mean they aren't horrible; it just means that that's all they are).

I would resist trying to "control" your thoughts. This will backfire. If you try really hard not to think of a pink elephant, I can guarantee you that you will think about a pink elephant a lot. I recommend aiming for ACCEPTANCE of anxious thoughts and states. This is difficult, but with practice, it works. Panic is often caused largely by the REACTION TO an uncomfortable feeling and anxious thought; we get anxious about being anxious. We don't understand (read: can't accept) what we're feeling or thinking and this magnifies our anxiety enormously.

If you're up for reading up on anxiety, I would recommend Paul Foxman's book Dancing with Fear. Some of what you describe also sounds like it could be OCD (you mentioned intrusive thoughts), so if you're able to, you could do some basic reading on this as well. Jonathan Grayson's book Freedom from Obsessive Compuslive Disorder would be an excellent place to start. Otherwise, you can get good infomation for free online at the National Institute of Mental Health's (NIMH) website:

http://nimh.nih.gov/index.shtml

If you scroll down a bit, you can click on 'panic disorder' and 'obsessive-compulsive disorder'.

More importantly, do you have access to a therapist that specializes in anxiety disorders? As for medication, I'm on Clonazepam and it has done wonders for my anxiety (I have OCD with a strong panic component). SSRIs like Citalopram have not helped with my anxiety.