Two months is actually a solid runway for CR and DS specifically. Here's what worked for me when I was stuck in the 600s on those two sections.
For CR, the shift that made the biggest difference was stopping treating every question the same way. Assumption questions and Weaken questions look similar on the surface but require different thinking. On Assumption, I started asking "what does the argument silently depend on being true?" before reading the answer choices. On Weaken, I was looking for something that breaks the connection between the evidence and the conclusion. Mixing up these two approaches late in prep was where I kept dropping points.
Practically: I did sets of 10 CR questions, but grouped by type, not randomly. Doing 10 Strengthen questions in a row helped me feel the pattern in my bones. Random practice feels like prep but it can hide the fact that you're actually weak on a specific type.
For Data Sufficiency, the single best thing I did was stop picking answer choices and start writing out my analysis on paper first. Something like: "S1 alone -- what do I actually know? What's still unknown?" Then S2. Then both. I was so much faster once I stopped confusing "I feel like I have enough info" with "I can prove a unique answer." Those are very different things.
One more thing -- if DS is your pain point, go back and look at what type of DS mistakes you're making. Are you picking D when it should be C? Are you picking E when one statement was actually sufficient? Those patterns point to different fixes and you don't want to waste 2 months solving the wrong problem.
What's your current score range on CR and DS if you know?