Restore existing iPhone from iCloud I am looking to restore my current iPhone from iCloud because I've accidentally deleted WhatsApp and want to recover the conversations.

I am nervous to do a reset in case I lose more than I bargained for. Does everything come back to your phone if you reset and restore from icloud. I have a back up as of yesterday and have now turned it off so that it doesn't back up again before I can restore. I have googled this and everything is to do with new set up. I saw  your post re this but wanted to double check before I click "reset" thanks
Yes, you can. Just reset and restore. The backup is from yesterday, so only that information will be lost which you added today. Everything will come back. But it will take time if you have a large camera roll or lots of apps.