The police shifts are horrible. I used to work rotating shifts and after 12 years of them I took a 10k pay drop to get off as I couldn't take them any longer.
Night shifts in particular if you are not used to them, (sorry Porg nannies don't work all night long), are very debilitating over long periods especially if you ain't young any more.
While I could cope and even enjoyed them when younger I would jump off a high bridge rather than go back again. 35ish was old enough to get a sensible job that meant I actually got to go to bed when it was dark rather than wandering around the streets at 4am (wasn't police but some of the things like this were the same)
If this takes away your confidence then are you sure you want to be fuzz? You'll get a lot worse than this