How can I deal with my ex being in my group of friends

It's been 3 months, we were never really together but I loved her deeply (it was my first love). She was not in love and leaved me when she found out I was. It lasted 3 months.

Problem is we have some close friends in common. At first I tried to keep her on insta, keep talking on the group chat like nothing happened. But in the end it was just making me suffer. For a month now I've muted and not read the group chat, I'm starting to mute some of my friends stories on insta because she keeps showing up and seeing her makes me feel bad.

The fact is that I have been with that group of friends for 12 years, for her it's only been one. I don't want to leave that group but I don't want them to make a choice or anything like that. The thing is that I'm missing events just to avoid seeing her and I don't know how to feel about that.

I know time will help and all but right now I'm feeling bad and need advice / reassurance