I feel your pain! I'd done well in all of my courses, and then I go and totally bomb the GRE (I got a 1070 overall)! I thought I had done pretty ok on the test, but my scores aren't surprising, given that I usually freak out during tests like that. I'd talk to POIs at the schools you want to apply to and get a feel for what kind of GRE scores they're expecting, and how much weight is given to them. Usually, there are other parts of your application that are much, much more important. For, instance, my POI said that she doesn't really care about GRE scores, since she knows that there are some people that just don't do well on standardized tests and the GRE isn't a really good measure of how someone will perform in a graduate program.
With that said, I'd still retake it! Get a book, and just work your way through the whole hefty thing. The GRE can be studied for, and preparing yourself will give you a better idea of what to expect.
best of luck!