How do I stop using my phone in the middle of the night?

Ho – I think it will be useful to see what thoughts and emotions push you to get your phone out in the middle of the night
I have set a time lock so my phone apps go “to sleep” at 10pm and wake up at 6am and if I wish to use them during the night I have to “break” their pause – that always poses a question on what sort of urgency brings me to do so!
My only real advice is to exercise your discipline as the phone is only an external device that shows you all your attention is constantly outside yourself

I stop using my phone in the middle of the night, by turning off notifications so I won’t get tempted to look at my phone.

Turn the flight mode on and put it face down. It's best to keep is out of the room or at least on the other side of the room so that you have to put in more effort than worth to get to it at night.

Turn on Do Not Disturb Mode so that my phone does not light up. Put the phone on the other side of my room or simply do not keep it in the room at all

I disable all connections (Wi-Fi, 4G etc) so I don't get notifications. Everything can wait until tomorrow. I have also disabled notifications for all social apps ( and deleted most of them as well) so I use them ONLY when I want to.