I am sure RC is not as hard to improve in your situation as it seems. To get from -18 to -9 is double in a couple of months.
I can help you with RC for free. Please don't hesitate to PM me to meet via Zoom
October is 3 months away from now. While we can take as many prep-tests as possible to keep our mind sharp, we cannot do one set every day. What do you guys do on days that you are not practicing Prep-tests? Doing problem sets? Or reviewing?