Should I retake SAT BIo and SAT US history?

[hoolia]

I'm going to be a senior in high school. I just got back my SAT scores from June. I got 650 on SAT Bio and 680 on SAT US. I hecka studied for them. I even read the study guide books millions of times and I still got below 700. Is there something wrong with my study habits? Why am I still getting low scores? I practically studied my butt off and now I feel so depressed. Is it possible that I can retake the tests as a senior? If I restudy for these tests what should I change about my study habits? Why is that even though I study I still get low scores? Maybe I'm stupid...I dunno ...I just feel so depressed right now. please help