You don't have to waste your time like that. When you do CR questions, try to read fast as long as you understand the meaning. Gradually, you can improve you reading skills by a lot after doing CR in the OG for two time. You will see the difference after two rounds. Believe me.
I am not sure what other suggestion to give you other than the one above. But just keep one thing in mind: reading comprehension comes from extensive reading experience. Try to read one English article a day as fast as you can when you still understand the meaning of it.