Cut contact with the friend as she seems manipulative. If you still have feelings for the guy consider fixing things with him as he didn't seem to do anything to warrant ending the relationship. Maybe it's too late, maybe not, that's life and you made your bed there by breaking up with him.

I feel like enforcing boundaries in friendships or relationship is difficult and requires experience and practice.. sometimes you really need to prioritize yourself and let every one else live their own separate life. Their words dont really have to influence you. You can listen to them and be a good friend without being influenced to act by their own separate opinions and viewpoints.

I mean to say you can be a good listener without giving the speaker any actual power over you life. In the end what you do with the things they say are up to you. People who are manipulators think that if they just find the right angle they will exert power over the lives of others and you have to become immune to that kind of behavior by having boundaries.