For context. I am married and have an additional bf. My spouse and I have been together for almost 10 years.

My bf and I have been together for 9 months and are both poly. He recently had his ex reach out to him and from what I understand the relationship was extremely toxic and potentially manipulative. I only know the story from his spouse, he has not told me a single thing about it other than he is still grieving. I have had really bad anxiety about us for a while and feeling secure in our relationship. Now knowing that they may be talking again makes my anxiety even worse. I was told at one point this ex sabotaged several of his relationships because she wanted all his time to herself. I’m worried that if they get back together, she’s going to make him choose and that I am going to lose him. I know I have attachment issues and am actively in therapy working on them. How do I either find confidence in my position as a partner or come to terms with the fact that he’s gonna do what he wants and there’s nothing I can do to stop him?