You got this! I passed on my 3rd attempt in October, you can do it in your first, especially with it being CBT!
I think its quieter on the Enviro boards because no one is crazy enough to sign up for the Enviro exam, even when it was still paper-and-pencil. Or its just not a commonly taken exam. I think if you're adequately prepared, the exam will seem easy. I took it this past October, the last time it'd be offered as pencil-and-paper. I thought after the first hour or so that I would be taking the exam again in April 2019, but after the 2nd or 3rd pass through the exam problems I was (almost) slapping myself, thinking "Why didn't I see that before? This problem takes 30 seconds to solve," or "Wait, wasn't the method to solve this problem tabbed in one of my references?"
With the Enviro exam moving to CBT, I think there is going to be a shift in how an examinee prepares for this exam. In the past, for this PE exam, you would be responsible for gathering your references, knowing them, and "hoping" they would be the "correct" references to get the correct answers. Whereas the FE exam and the CBT PE exams, where you can't rely on extra references, other than the one you are given. When I was studying for the FE exam, I bought the reference manual while I was studying and (almost) memorized where everything was.
With that in mind, the best advice I could give is to work problems, work problems, work problems, be familiar with the supplied reference manual, and memorize key concepts and conversions (like 1 psi = 2.31 ft) that aren't in the supplied reference manual. If you bought the NCEES practice exam and the current sample exams/problem sets and have a good understanding of the problems that could be on the exam, you should be well prepared.
Wishing you good luck and a big green PASS in the very near future
When you go back to take it, you will conquer it!