How do I cope with separation anxiety while boyfriend is out of town?

Relationships at any amount of distance can be so hard! It makes sense that you are encountering more anxiety than usual given that major change in your relationship. And you're right that being separated from our partners can heighten our insecurities and worries about not only our relationship security but about our partner's interest. Have you talked with your boyfriend about this struggle you're feeling? It can be hard to have this kind of conversation without triggering a sense of blame and subsequent defensiveness in our partners, but it really is possible. If you have any concerns about being able to do this, then a session or two with a local counselor or therapist might be really helpful - and it really can be just about finding the way to share what you're feeling.

As far as coping with anxiety, there are a lot of options but I highly recommend an app called Self-Help for Anxiety Management. There's so much good information in this app to help you learn to pay attention to what kinds of thoughts are helpful or unhelpful, and there are also lots of activities for calming down and decreasing the intensity of that anxiety. The best part is, it's free!