I got immediately depressed when my sister & mom came home from vacation....?

My mom and sister have been on vacation for the past week and a half. I've had the entire house to myself and things have been peaceful and clean. I've been 100x's happier than I've been in MONTHS. Truth be told, I wasn't looking forward to them coming home at all. In fact, I was rather glad that they were gone. As soon as they walked in the door, my mood shot down about 100%. I feel shitty, depressed, annoyed, pissed off... I wish they were still on vacation honestly. I enjoyed being alone without them. Don't suggest moving out - I'm a minor. I'm now stuck in my room. I could leave, but I really don't want to be around them. At all. I'm not complaining about life... not saying they're terrible people or that I have a miserable family. None of that. I just want to be alone again. My sister is 18, but doesn't go to school or work... so she is home 24/7. I'm not allowed to leave the house, because my mom fears I'll get abducted. In all honesty, if my sister was gone... I'd be fine with them being home, I think. What can I do to stop being so down? I hate being this way, but I really am annoyed and angry that they are here. It was nice to have the house quiet and peaceful for a week or so.... What can I do to bring myself up? I'm tired of being so down and letting them get me down. Doesn't help that my mom constantly sides with my sister, so if in a feud.... my mom will automatically agree with my sister (wrong or right). I just want to be okay, because I have nowhere else to go.... Any tips? Please?