Shostakovich 2nd piano concerto, 3rd mov,need help

[s1d1f1]

Hello,
I play this concerto for three-and a half months,and it's has been like a rolercoster ride,but now the date of my performance is very near,so I need advice about how to have strainght to ,,survive'' the passages,of paralel sexts (the parth when the timpans are just solo with piano)...I really tried everything,but is there any way how to not ,,fall apart''? because it's lasting very long,and it's exausting/

Ofcourse anyone who would have any suggestion is welcome to answer!!

&feature=related   in the 1:30 ,he slows down wich is a very bad thing though...