Remember that you're trying to get better.
And practice shouldn't be frustrating as you bang your head against the wall, over and over again.
So...if you're practicing ACT reading, why not read the passage OUT LOUD?
It's not embarrassing, because you're the only one in the room.
OK - if someone else is in the room, whisper or move your lips as you're reading.
Time yourself reading "out loud," and let that be the standard for your initial enlightened skim of the passage.
Here's what I mean: let's say you read a social science passage out loud, and it takes you 3 minutes and 34 seconds to read the whole thing. You read much more slowly if you're reading out loud and focusing on every word, right? So you shouldn't take more than 3:34 to read the passage in your head.
The key to translating what you do out loud to what you will do in the actual test is ACTIVE reading. I use the underlining and highlighting functions on Adobe to help me to remember where key words and phrases are located in the passage, and so should you.
Better yet - why not print out the reading passage and highlight/underline it yourself?
This is definitely worth a shot. Post clips of yourself reading a paragraph of your next ACT reading passage below!