Hey Franklin,
Just my two cents:
Keep your confidence up on your second go-around. The first time I prepared, I worked through three books and completed about 10 practice exams. I scored 650 and 680 on the first two, and over 700 on the rest. These were the same exams that my brother practiced with. We scored roughly the same on these practice exams and he ended up with a 740 on test day. I felt confident going in.
I scored 600 on my first attempt. I was a bit sick but I wrote anyways. I thought being sick wouldn't affect me much, plus I didn't want to lose my stupid $300. I pretty much ended up in a mental mess during the test. I took me four and a half minutes to finish the first Quant question, then I started thinking about being behind on the timing, then I started thinking that I shouldn't have sat to write the test while being sick, then about how much work I put into prep, etc. It was a disaster and I was devastated afterwards.
I knew right away that I would re-take the test, but I didn't feel confident at all. I went through all of the prep material again, and started ordering and purchasing all sorts of practice exams. I scored well on all of the practice exams, as I did during my first prep, so I really didn't know how to gauge my capabilities. Needless to say, I was very nervous when I wrote the second time. It ended up going well though. I just stayed calm, and ended up with 750, which was on the high end of my practice scores.
I guess what I am trying to say is that the practice tests seem to be pretty accurate. If you can legitimately score over 700 at home, you can probably do it on test day. Don't let one bad day mess you up too much. Stay confident and you will do well.
Cheers