motivation and tips for my upcoming SAT in October (Goal: 1500)

I’m confident by October that I can score 750 plus on my reading/writing sat score, but I’m have trouble with math. Every time I move onto the math no calc I’m just so brain dead after all the reading. And to make it worse my math score is pretty terrible considering I want to score a 1500. How do I overcome this? I’ve been studying for a month now and I’m just starting to do full practice tests in one go. In the past only doing each section at a time. I’m still grinding away the math sections, re learning, understanding and applying these concepts during the test How long is this gonna take before it gets easier? What other tips are there for me to hammer the SAT math and get my 1500. All the help and motivation is greatly appreciated.