Here is my 2 cents. CATs help to get familiar with GMAT but they do not improve your score! (maybe a little bit at the begining). What you should do now is to dive into your mistakes. Mistakes is the main source of your improvement. So, try to understand why you did a mistake: lack of concept? silly mistake? tricky answer options? unknown words? lack of concentration? not enough time? slow reading? I see you have GMAT ToolKit, use Bookmarks and Review there. It's better to solve less questions but really get why you did some of them wrong and be sure you will not repeat the same mistake next time. If you see you answer the same question wrong again, that should ring a bell - you not working enough with mistakes.
Post here specific types of mistakes you make and I could give more specific advice. Sometimes it can be not so obvious. For example, if you spend too much time on RC questions, you may decrease time per SC question under 1 min to have more time for RC.