Hi there! This isn't supposed to sound at all snarky, but have you considered trying a timed practice test whereby you actually read each passage? I'm suggesting this, because I was just like you a few months ago - I often scored 17-19 on RC. I used the Kaplan method, skimming as fast as I could, jotting down keywords, skipping sentences, and generally panicking about how little I absorbed. Then when it came to answering the questions, I would have no clue where to search. And, like you, I found that minutes would dwindle as I looked for the keywords. And tackling question 6 while already 15 minutes down kind of makes you want to puke.
So I stopped all the tricks and strategies and decided to give reading a whirl. And I'm someone who HATES reading on-line. I think people have a hard time with RC because there's so much time pressure, and in my opinion, the search and destroy method only makes it worse - you spend so much time digging.
Now, with so little time before your test, the most important thing is to approach this section with a method that you're comfortable with. But it might be interesting to see if there's any improvement in your score by the reading method. If you do decide to try this, I'd recommend reading about 3/4 of the paragraphs. Every word, every sentence. And jot down some dates and names on your scratchboard as a crutch. By the final paragraphs, you've already gotten a good sense of the passage, and I would only read the first sentence of each paragraph at that point. What I found was that after reading carefully, but fairly quickly, I knew where to search, and sometimes I could remember the answer off the top of my head! And while I was reading, I didn't think about the questions. That was just my time to read, about 5-6 minutes per passage. And it worked! I got a 25 on RC.
So good luck. Last parting thought is that I found the actual DAT RC much easier than any practice test I encountered. It's not that the passages are less convoluted, but the questions themselves seemed much more straightforward. You'll do great!