Photoshop updated and I have lost all of my styles, brushes and actions. Is there a way to find them to add them back and how do I prevent this from happening in the future?

You need to find an older version folder or system backup of the preset files. Various preset file locations listed here:

https://helpx.adobe.com/au/photoshop/kb/preference-file-names-locations-photoshop.html

More details on actions, however, this applies for other preset files, not just actions.

Loaded .atn files or newly created and unsaved action sets are temporarily stored in the Actions Palette presets file (Actions Palette.psp). This file should be considered temporary and may be subject to corruption or loss, which is why making an explicit save to .atn file for each individual action set is strongly advised.

The Actions Palette.psp file can often be used to migrate the entire panel/palette or to possibly retrieve unsaved actions. This is by no means a replacement for saving each Action Set as an individual .atn file. The location of the Actions Palette.psp file can be found in locations similar to:
 

Mac:

• /Users/username/Library/Preferences/Adobe Photoshop CC 2022 Settings⁩/Actions Palette.psp

Win:

• C:\Users\username\appData\Roaming\Adobe\Adobe Photoshop 2022\Adobe Photoshop 2022 Settings\Actions Palette.psp 

(Replace “username” with your user account name and also replace 2022 with your version name/number. The Windows appData or Mac Library directory may be hidden. You can search the web for how to make hidden folders visible for your OS if this is the case).

https://prepression.blogspot.com/2017/01/photoshop-custom-action-file-backup.html