My wife and I lived 6 hours apart when we were first dating. A few weekends out of that time when I wasn't visiting her, I would be anxious because I didn't know what she was doing. A couple times she asked if I minded if she went out with some friends to the bar (and she named who they were). At those times I would say I was almost panicked. But she always called me afterward and always told me about it. I always had to remind myself that she wasn't my ex.
This pattern continued which comforted me and led me to feel a trust that I hadn't in a long time. Unfortunately I trusted too much. So with regard to your P.S.; if I ever get over this type of anxiety AGAIN, I will certainly tell you how.