Did I screw myself over for rounds 19 and 20

i don't understand these new currency system. I used a bunch of lightning energy on the bonus Stache and probably my keys too. Am I fucked for the challenges rounds 19 and 20? In the end it doesn't really matter because all I've pulled, aside from a bunch of SR are 2 epics, 1 ultra.

for the next challenge like this, should I NOT DO ANYTHING except rounds 1 thru 20 with the keys and lightning bolts?