Overly controlling parenting

Ok so this weekend's the first time my parents have let me stay home longer then a few hours alone, my mom was asking me if her leaving me home alone for 2 days makes her a bad mom. I'm 18. They hardly let me leave the house to even just hang out with the one friend I have that I actually like that they are willing to let me be friends with, when I want to do anything with anyone in my life my parents expect me to have them over at our house with them home where they can watch everything we do. They still try to go through my phone constantly, they get mad when I close or lock any doors, even when I'm in the shower, if I lock the door they take the handle away because they get upset when they can't just barge in on anything in doing. I don't smoke, I don't drink, I don't do drugs, I don't like partying, and my parents never even really give me the freedom to even have considered it, yet they act like somehow in the 5 minutes of breathing room a day that they give me that I'm somehow acting out and doing crazy stuff. My mom flips out if I express any desire to move out and have my own life, she tries to hold money over my head, threatening to not help me with college or really anything even though they definitely can afford it, and have put my 3 older sisters through however much education they decided was right for them and still have enough left for me, and I can't save up for it if they won't let me have even the freedom to get a job without them controlling my incom and my mom trying to take my money, I honestly don't know what to do anymore.