That said, since the phone issue may also be causing a feedback loop of anxiety, I'd suggest a few things.
1. Schedule "phone time". Set an alarm for when it's over, and commit to not using it outside of that time.
2. Set "Do Not Disturb" on your phone. At least with Android you can do this just by talking to the phone. Or at the very least set quiet hours for the majority of the day.
Alternatively, (2) may cause more anxiety if you're constantly wondering "but what if" - in which case, perhaps set it to whatever is necessary to hear it, but tell your friends/ family that you're trying to stick to specific hours for phone calls/ texts.
3. Some sort of cognitive behavioral approach. Think about what triggers you looking at your phone, or your anxiety - write this all down. For every trigger, consider what actions you could use to directly address that trigger, in a healthier way. This could be as simple as counting to ten or focusing on your breathing when you feel that anxiety, giving your mind some time to rest.
Consider writing down when you feel that anxiety. Instead of turning to your phone, perhaps just with pen/paper, write down what you were doing, how you're feeling, and how you'll move past those feelings.
4. Log out of accounts. Even just having to log back in can force a pause, and give you a chance to back off. Remove distraction apps entirely. Don't just rely on blocking them or whatever - uninstall them. When you're feeling better, and have healthier habits, you can reintroduce them.