adjustments for fast greens

my club is getting ready to host a pro event in the next month, they've started to speed up the greens substantially.I am STRUGGLING. Went from slow greens coming out of winter where I was putting 33ish strokes per round.

Had 40 putts yesterday and so many 100 and in shots that I left short for fear of not holding the greens. 15 handicap so not able to get backspin regularly enough to attack them.

Other than trying to be short which is leaving me off the green and with really long putts, what else do I do? Killing my scores for the last few rounds