I think you should always be drilling LG, almost on a daily basis. I try to do 3-4 games per day to stay sharp. I've found when I get lax about this, my LG scores go down.
Yeah ... You can't fix anything at this point. Sorry. Either you're ready or you're not. PTscores are not the only way to gauge readiness. You should already know without needing those scores to confirm.
... prep courses and when my scores plateaued I was extremely frustrated ... a significant impact raising my PTscores. As @"Nicole Hopkins" said there ... clearer providing more confidence when PT'ing.
All the best ...
... 15ish questions compared to your PTscores. Fixing that gap alone would ... might have to reuse some PT's, as you seem to ... . Take the last three fresh PT's closer to the test ...