A great way to know is if you can’t go anywhere without your phone, and if you do you think about it all the time. If you can’t leave it anywhere, and you can’t leave it for a few hours but you’re always checking it.
I totally agree with Valeria, if you are incapable of leaving your phone, definitely is a smartphone obsession. Checking all the time, even if you didn’t receive any messages or calls.
Yes, try to spend some time without.. and be more aware of your actions! be aware of how much time do you spend on it and if that is affecting your social life