Painful thoughts concerning bf’s plans

I’m dealing with some pretty intense insecurity, and I am allowing it to distract me from my SCS work and from my ultimate goal, which is to improve my relationship by moving towards seeking validation from myself instead of my boyfriend.

Right now, my bf is on a big work trip in a different city. He has an old friend there named Sally, who I’ve never met. She is from his home city, and my bf and I have been dating just over a year, so it’s not surprising that I haven’t met her, given she lives in a different city entirely. I don’t have evidence to suggest that he would cheat on me with Sally, but the fact that I don’t know her and that I can’t be there and that I know I can’t just ask him NOT to hang out with her is giving me extreme insecurity. Too many unknowns. I want to trust him. I don’t think he would do that… but I guess part of me is worried because it’s technically possible. Anything is possible, right?

This issue is eating me from the inside out. I’m trying to be the cool girlfriend who lets her boyfriend be himself and do what he’s going to do, but all I want to do is tell him that I’m uncomfortable with him hanging out with another girl in a different city. I know he’d probably get impatient and
mad that I “don’t trust him” and it’d turn into a whole big issue, but I HATE that he thinks it’s okay. He’d be jealous and insecure too if I did the same thing to him.

I listened to the podcast on self-sabotage, because I feel like my urges to try to tell him what to do fall along those lines. Here is my model based on that:

C: Bf has plans to hang out on Friday with an old friend of his from his home city named Sarah. He says, “some of her friends from the same city will be there”. I’ve never met Sarah. I am not in the same city right now, so I can’t go.
T: It’s possible he could cheat on me.
F: Insecurity
A: I self-sabotage my progress in moving away from seeking validation from my bf, and trying not to control or change him
R: ?? I’m not sure. I cheat myself out of peace of mind? Or following through with my goal?

This issue is unreasonably painful…. I want to believe he’s doing nothing wrong but it’s so hard to get my mind there. I feel like I’m doing 10 models/thought downloads a day until Friday passes. Any suggestions on how to move past this?