I'm back

Do you have any advice for more math practice?
I've worked through OG11/12, the Veritas Set, Kaplan 800, Cracking the GMAT. I can't go through those questions again, they are too easy.
I've done the Knewton Math quant, Gmat Club diagnostic test, Math 25 set on this site. Is it worth doing the free Manhattan Challenge sets? I've only done half a
MGMAT Challenge (#4) test but I think it is way too hard to be realistic? At least if I compare to the CAT's I've taken.
I only have two weeks left so I think my ROI would be higher if I put more effort into minimizing my errors and weak areas instead of doing unrealistic hard questions not likely to show up on the GMAT?
Do you have any recommendation for free geometry practice (hard difficulty) ?