Beep test performance declining instead of increasing

[Madsimps]

Hey so,
I have my army fitness test next week and need 7.5, which isn’t that high but I’ve always struggled with running.
But I’ve been training for it and improving, and a few days ago achieved a 7.1 and then 7.1 again the next time.
I was feeling good like I would definitely get the 7.5 on the actual day with the extra adrenaline and drive to push myself during the official test.
But then yesterday I got a 5.1 and today I got 5.6.
Am I somehow declining in fitness or am I just patching myself out. Or is it that I’ve been doing it too often and not allowing myself time to recover.
I was hoping with my pattern up until now that I’d pass the test and then by January when I leave would be doing even better, more into the 8’s or 9’s, as I had previously been improving by 3-4 shuttles each time. But now I’m struggling and panicking that I’m not even going to pass. Is there something I’ve been doing wrong or is it all in my head?
And once again I know 7.5 shouldn’t be this hard to get, it’s not out of my reach to be fit enough for the army, I’ve just spent the last couple of years focusing a lot more on strength which is why my cardio has suffered, so please be nice lol