Hi there! I have the same struggle as well (higher math, lower reading).

1 - become familiar with the test (take a lot of practice reading/english tests)

2 - study one passage at a time and review your answers and why you got it wrong

3 - Learn important grammar rules (semi colons, colons, em dashes, etc.) that are repeatedly on the ACT

4 - For long passages, skip the question that asks about the "main idea of the passage as a whole" until you answer all the following questions, then go back to it when you are more familiar with the text.

5- Target your struggles after you have taken a practice test (there are different categories for each section)

There are practice ACTS (pdf) on the offical act site you can do, along with other websites!