Definitely not overreacting, even the extra context in the comments. I agree with getting a contract drawn up. I'd say it's not worth going forward but I know the place you're in right now isn't great (how many times have you been broken into?!) How do parents feel about your siblings making use of the space when they're in town? It's lovely they want to help you, but it sounds like they're really hoping to help themselves just as much.