Getting used to altitude is not that big a deal if you prep yourself aerobically ahead of time. The week before the summer seminar, I could probably run barely a 5:10 mile (track season had just ended and I took my 3 week break) but at the seminar I was able to run a 5:30 for their CFA. They tell you ahead of time that if you are in good shape, the altitude is easy to adjust to.
Anyways I feel like we are getting a bit off topic lol. Yes, the CFA is used to see if you would be able to pass future physical assessment tests.
Imo, you were not anywhere near prepared for the test because you didn't work on each event in succession at least once or twice. I was like you, except I started taking CFAs early so I had time for another test (and I didn't have to take it at 6 in the morning so props to you for that). The second time I took the test my mile time dropped from a 5:20 to a 5:12 just because I had done the CFA before and knew how sh*tty it feels. The CFA just measures how much pain you can take in succession, so push yourself in training. Don't do push-ups until it's uncomfortable, do it until your arms feel like noodles and you can't do anymore. 2 weeks of a challenging push-up regime will do wonders. What I did before to get push-ups up from 70 to 120 in 3 weeks was 3 sets of my (current max reps-10) + 3 sets of diamond+wide push-ups (you do same number of push-ups as in your normal sets, but half are diamond half are wide and you don't take a break in between diamond and wide). The break in between sets is as long as you need. Then a couple times a week I would do 3 sets of 40 chair dips (so your number of dips would be -20 from normal sets). I remember straight up hating push-ups after those three weeks especially because I did that workout daily, but I never had to do serious pushup workouts again (2 years later I can still do 80 in 2 minutes easily). To get my core stronger for sit-ups, I did a ton of bicycle crunches and planks. I didn't really follow a regime though, but you will know what failure feels like. Reach that point, then try to push past because that's what will give quick results. For pullups practice calling cadence in your head. I did 3 sets of 10(for you maybe it'd be like 5) then after those three sets do 3x5 negatives (jump up to the bar and drop slowly for about 5 seconds)
As for your shuttle, I don't know what to tell you. I was barely able to go from 9.9 to 9 flat, but that was just from practice. The CFA really is just a measure of your common sense. Do you have the common sense to workout, practice and perfect it? Best of luck to you OP, and remember if you want something badly enough, you make time for it!
The human body is pretty amazing. You can doo eet!