Parents not understanding

So my parents told me that a friend of theirs is moving into the guest bedroom in the basement for college, and I was asking questions about his person, they came over to check out the room and said that If he is still here in the country, he will take the room, there are 4 bedrooms in our house all but one are occupied. Then after the guest leaves my parents tell me that a different person is moving in, taking my sisters room (my sister will then move into my parents room) then the guest will move into my sisters room which happens to be beside my room. Now I’m mad at this because I won’t be able to do a lot of stuff, I have to be quiet all the time, I have to share the bathroom with a person I only met once. And my parents don’t understand because the same situation happens 2 years ago in my old house, and they said I did not have to be quiet, but they ended grounding me for 1 month because someone was taking an online exam and something from my room dropped on the ground. And I told them that the same thing is gonna happen and I’m gonna have to live like a mouse, I don’t want to confront my parents because they are going to scold me for being ungrateful when I’m just sharing my thoughts.