Utilities folder disappeared

All those apps are still on your iPhone and are in the App Library. The App Library is the last Home Screen on your iPhone when you continue to SWIPE LEFT until you reach it. Once you are in the App Library, then you can search and find those apps. Once found, then you can DRAG the apps out of there and place them on your favorite spots of the Home Screen.

Axel F.

In continuation to what Axel Foley has said.

It may also happen that a few Home Screen may have been hidden See the pic below

Probably some pages may be hidden

Here's how to hide/unhide a page:

1. Touch and hold an empty area on your Home Screen.
2. Tap the dots near the bottom of your screen.
3. Tap and Tick the circle under the page that you want to unhide.
4. Tap Done.

Please see the pic below which is self-explanatory