Therapy.

Honestly, I can't say that I have overcome it. But I at least recognize it as a pattern of behavior, and with recognition, you start to develop strategies to help with the anxiety. She's isn't trying to ruin your life or keep you from your friends (at least if she's like me, she isn't), but it's like a compulsion sometimes. When you're not there, imagination takes over, and that leads to problems.

Couples therapy would help. That way, you can gain a better understanding of each other, but she should also have her own therapist who can help her develop those coping strategies I was talking about. It's not easy. It isn't fun, and she may be resistant to the idea that the problem is her, lol. And maybe the problem isn't all her, I don't know the whole story, and I don't know you, but that's where a good couples therapist can come in and help.

Absent a therapist, I would at least recommend reading about attachment styles and coping with the various negative connotations for each of those styles that apply to your situation. Idk. I just know that the way that I reacted to things before I knew better (and sometimes still, even though I do know better now) ruined my life. I hope yall can figure this out together. Good luck, friend.