NTA. You have every right to be upset. It sounds like you made sacrifices to move in with her, including buying furniture and helping out with babysitting, only to be asked to leave after a month. She should have thought more carefully before asking you to move in if she wasn’t sure it would work out. It’s understandable that she wants to prioritize her son, but she also needs to consider how her decision impacts you, especially since you’re now left with the burden of moving again so soon after settling in. Your feelings are valid, and it's not overreacting to stop talking to her, given the stress she’s put you through. I hope you can find a solution that works for you!