Firstly, please remember, not passing the PE exam does not make you any worse of an engineer than you were before you took the exam.
Take some time off to relax and process your diagnostic report, and decide how you want to attack studying in your next attempt. Whatever you decide (review course, self study, etc.), make a plan and stick to it.
Pick up the studying again, do as many practice problems as you're able, and take this exam down come April!
It's worth noting that there are a LOT of EBers who did not pass on their first try. After you pass, it doesn't even matter how many tries it took you. And personally, it is my belief that the more times you fail the PE exam, the more sweet it is when you finally pass!