Stressed for the OAT

Hi I was planning on applying this upcoming Fall 2017 but I'm not too sure anymore. I've been taking Practice Kaplan tests and been studying for the last 4 months for the OAT but I haven't made any improvements. Any advice? I'm not sure what to do. As of right now I was planning to take the OAT at the end of July but my scores haven't even reached 300

Scores:
Bio-250
Gen Chem- 260
Ochem-270
Reading Comp- 290
Physics- 230
QR-230