I just joined this community yesterday, but I know that there are a lot of people out there that are currently getting some really awful news.
While I am by no means an expert in test taking, I feel like I am somewhat qualified to offer some advice. I've taken four different NCEES exams, failing three of them - (FS Fail, FS Pass, FE Pass, PS Fail, PS Pass, PE Fail, PE Pass). If NCEES ever goes public, I'll buy stock.
So for those who failed:
1) Take a Deep Breath: You're currently feeling a lot of emotions right now, and they're likely all negative. You poured countless hours and hundreds of dollars into this exam, and are feeling like it was all for nothing. It wasn't for nothing. You're now closer to passing the exam than you ever have been. This might feel like a huge set back, but it's a necessary step forward toward your license. Some people get there in one big step, while others take many small steps to get to their destination.
2) Prepare for Returning to Work: For me, this was the worst part of failing the exams. Having to explain my failure to co-workers, many of whom had already passed the PE or PS exam, was really difficult. In your mind, you likely think that colleagues are judging you more than they really are. The reality is that they are almost always sympathetic and feel badly for you. I've read some horror stories in the past where co-workers will verbally put down or make fun of someone who has failed - if this happens to you, I am so very sorry. That is truly a bad situation for so many reasons. But, 99% of the time, your co-workers will be sympathetic.
3) Take a Break: Every time I failed, my gut instinct was to jump right back on the horse and immediately start studying again. This is a positive mentality to have, but it might not be the most productive for passing this exam. Your first reaction might be, "But I've had a break for the past 6-8 weeks since I took my test". In reality, you haven't had a break. You've been stressing over the results, possibly losing sleep. Now that you know that you've failed and that you will have the opportunity to take the exam again, it's time to rest and clear your mind. You know what lies in your future, but for the next month, try to rest and make a plan.
4) Plan Your Move: One of the few benefits to failing is that you are presented with a report showing your weaknesses. Depending on how the exam went and what you know about yourself, this may or may not help you. For instance, my first PE fail showed that I was basically below average on everything except surveying. For me, it was completely back to the drawing board, but if you know that you're extremely strong in certain categories, terribly weak in others, and your results show this, then use it to your advantage when you start studying again.
5) Hop Back On the Horse: After a month of rest, pull out the crate of books that you last touched back in April, and slowly start studying again. If you took a prep class like EET or SoPE, look into if they offer a free 2nd attempt, or discounted classes for attempts beyond the 2nd attempt. If there were things that you didn't like about the class the first time, look into changing the school or instructor this time around (I had a difficult time following my geotech instructor the first time, and found that changing the instructor the 2nd time made all the difference). If you took a live class the first time and know where your weaknesses are this time, consider switching to on-demand if that's an option. This will allow you to spend more time on weak areas and less time on your strengths.
6) Pace Yourself: October is five months away. I won't lie - when taking a 2nd attempt and focusing on studying, those 5 months flew by. If you take a one month break, you have four months to study, and that is plenty of time. It's also plenty of time to completely burn yourself out. It's important to constantly study, but to also give your mind breaks. If your work is physically draining, plan on minimal studying on work days. If you must have weekends free, study 1-2 hrs a night, but give yourself a couple of nights off every week. Cramming and turning your brain to mush will do you no good in October - slow and steady wins the race.
7) When October Arrives, Relax: Stress is as much a factor in failing an exam as not being knowledgeable in your exam material. You will stress more going into this exam simply out of fear of failing again. Practice suppressing this fear, and know that you have an upper hand this time. You know what the test looks like. You know what the AM/PM time frame feels like. You've been here before. Reduce panic, skip questions that you are lost on, focus on what you know. (I realize all of this is easier said than done)
But for now - just breathe. Looking back, this moment will blend with all others. You will no longer look upon it as a negative experience, but rather a building block that was necessary to get where you are bound to go.
Best of luck!