I was told to lead a campaign and now they’re having conversations about it without me?

So I have just been placed on a PIP for two weeks. I work at a performing arts theater. And I am in charge of the Spring Campaign. Or so I thought. My coworker in Development and my supervisor have been keeping me out of meetings. When my coworker comes to my office to talk about the campaign, she does not acknowledge me. She just turns to my supervisor and started talking. She has gotten mad at me for not getting notes that she's been giving to my supervisor, who is not involved in this project at all. I feel like I should say something. I'm pissed off. I feel like I have to play Telephone to get any notes from her. I need advice.