[Virginia] Do I have a right to my space even if I don't pay rent?

I'm an unemployed 30 year old with a bunch of untreated mental illnesses like depression and likely adult ADD living with my parents. I just want to get that out of the way since I'm sure many Redditors will want to check out and call me names and say I deserved it for that.​The other day, my mom got in a car accident and my brother and his wife came over to help her out, since my family doesn't think very highly of me. Apparently our new puppy shit on the carpet and my brother demanded that I go down there immediately and clean up after it, shouting at me and going on about how useless I am and how I'm worse than those lazy Mexicans, and when I tell him "no", he started to try unplugging my computer equipment (which I bought with my own money, not that he would care). I got up to stop him, and he assaulted me, beating me in the head, breaking my glasses, knocking me to the floor, and busting my nose and ear.​I'm not really going to even bother going to the cops about it, since my mom is the homeowner and she already wants me out and has refused to tell my brother to leave, and has practically justified his actions by saying he's right that I don't contribute anything, giving the impression that I deserve to get beaten for not doing the dishes often enough. But the thing I'm interested in is something that my brother said when I told him to leave, and something my parents have said since I was about ten: "It's not your room, you don't pay bills, you don't help out, you just live here".​Are they legally correct? Does someone staying in a house who doesn't pay any bills or perform any services to "earn their keep" have no right to privacy? I know that if I don't have a right to privacy if I don't pay bills, then frankly no amount of doing the dishes or even paying rent would grant me that right unless it was an actual contractual agreement, but I'm still curious whether the excuse constantly given for exacerbating my depression is even legally grounded. If the cords and plugs my brother was pulling out weren't ones that I personally purchased (but were still purchased for me and used by me), would he have a legal right to have attacked me, under the argument that me getting up to push him away isn't protecting my property?​tl;dr: As someone getting free room and board, what are my rights against invasion of my space and people messing with my shit?