Screen is coming off my phone

I have a smartphone that I’ve had for a while now. I noticed some time ago that the screen was raised slightly at the top but it still seemed to work so I didn’t worry about it.

Yesterday, I was using the phone to read in bed and the position I was holding it in meant that it was screen side down. The screen just slid out of place.

It stayed attached the electronics, but it was no longer held in place. I pushed the screen back in. The phone still works - but I can now pull the screen out from its place with a finger nail or if I just hold the phone screen side down and wait for it to slide free.

If I don’t stop it falling it, it’s going to get damaged. Can I just glue the screen in place? I can’t see any way to make it stay otherwise.