i need to vent!!

so my boyfriend and I had to move back in with his parents and they are letting us use the backroom. okay no big deal. well my boyfriend and I are both 21 and he had a little sister who is 12. I guess him and his sister don't get along because his stepdad always let her get away with whatever she wants (since being here, I've personally seen it) and because she has this thing about doing things she knows is annoying as fuck to piss you off, just to piss you off and laugh about it. his parents will get so angry to the point of screaming and threatening to ground her and she just laughs, and they don't do anything anyways. or if she gets yelled at she just whines until they let her off the hook. it's driving me nuts. anyways so we found out that his parents and sister don't see this as our room it's the backroom (it was originally my boyfriend's room before we moved out when he was 19) and okay I get that but there's no door at all, no door frame, I just recently put a curtain up so we could have just a little privacy (turned out to be a semi sheer curtian so I'm also beating myself up over that). but his sister doesn't even knock or anything, she just barges in takes whatever she needs, or she'll just poke her head in to bug my boyfriend when we'll be laying in bed, watching a show before going to sleep. he's gotten on her about it before and she would just kinda blow it off like what he was saying didn't matter. well now I'm having the issue of his family (well his sister and step dad) take an abnormally long time in the bathroom. like a really long time. I have a younger sister so I have had to share a bathroom before but I feel so weird and out of place and I really love his family, we actually do get along. but we're all just driving each other nuts and I just need to get a place again just me and my boyfriend because I cant keep waking up every morning (all different times) and have to wait 45 minutes for someone to get out of the bathroom. they'll be in the bathroom for 20 minutes AFTER you knock and say you REALLY have to go. if you don't knock you could easily be waiting over an hour. i know it's such a strange thing to be upset about, but I'll be waiting so long that my bladder starts to cramp and hurt really bad and even after I pee, it'll be cramping the whole time I'm peeing, and then feel really sore afterwards. I'm not trying to get a bladder infection because I can never get into the bathroom. don't get me wrong, his parents gave us some place to stay, we give them $400 a month and are trying to save to get our own place and I truly appreciate them taking us in until we can but I'm going fucking crazy. I think I've actually gone in and out of severe depression since moving in here because his parents are the only ones who have a door, I can't even change in my own room I have to take clothes to the bathroom. idk ugh!! I might just be whining over petty shit, it's possible, I just needed to vent.