I'm curious what these tests are measuring if you say your reading comprehension is only 50%. Your comment here is completely articulate and sensible so you are obviously fluent in English.
Edited to add: hm. I just got 67%. I guess my college degree is a waste. Should have gone the humanities route instead.
In high school, there was an academic event for reading comprehension. I tried it one time and was humiliated. They read aloud to you a story, and then they ask you questions about it after. I have no idea where my head was, as I didn't do well at all. I never tried the event again. It wasn't until that experience before I realized that I'm the type that needs to read things multiple times for it to stick.
It hurts, doesn't it? I also thought a few measly questions would be a piece of cake, and mainly focused on speed.