Worried about burning through LG sections, general LG advice.

Hi all, I'm preparing for January and trying to tighten up my worst section, LG. My method has been to take 2 fresh LG sections a day, but I've almost exhausted all the core curriculum LG sections. I've been stagnating at around -4 for a few weeks, though in the last week my scores have been pretty erratic (-1 and -9). I'm worried that I'm wasting fresh sections, especially since it's possible I might be retaking in February or April. I'm also wondering what alternative strategies might be more effective at raising my score. I especially struggle with grouping/in out games. Thanks!