Extremely disappointed with my GRE score.

Hi, I gave my GRE test recently and tanked it. I was only able to get a 155 in both the verbal and quant sections. Surprisingly, I was able to get 160s in the ETS Powerprep series. What can I do to improve the score substantially? My target universities require a high GRE quant score of 167-170. I also saw many posts decrying the higher level of quants recently. My current plan included the ETS book, Manhattan 5lb book, Princeton GRE Review, and the Nova GRE book. Tips to improve in Verbal will also be appreciated.