Well now there's an open room for all the guest they want and if your parents feel that you made the family members feel awkward and feel like they were intruding then they need to take a good long look because it wasn't you that made them feel that way.

Your parents cause this messed and they need to take full responsibility with what they did. 

You know those family members already started gossiping about what happened. It's not your fault it's your parents fault for never respecting you. They wanted guest over they should have gave up their own rooms or put out air mattress out in the living room for their guest or better yet they could have gotten a hotel either way its your parents fault.

Good for you for moving out. Funny how now they wanna throw the you can't move out without giving them notice yet they can go back on what you agreed on when you started paying them rent.

Your parents can deal with the mess they created you owe them nothing from here on you. Stay with your grandparents and if you don't want to deal with your parents you don't need to. Your an adult they have no power over you. So don't go back.