I'm planning to live in UK for up to 6 months, please read, please help me out?

Ok, so I go to London often for holidays, I am from US and I plan to move to UK, I am 25 years old, going to be 26 and I am almost getting my bachelors degree. I study online and I have always taken online courses and no matter where I am, I can do my homework as long as I am aware of the time zone difference. I always do my homework at home but I want to gain a "living experience" in England. I live with my parents and I work at the same time to save my money for my trips to London especially I have cousins and friends in England. I go a lot, please don't judge. I love UK so much and I got back in August even though I had to go through a quarantine I normally go for a month during the summers and I go for two weeks during the winters. However, I am planning to cancel my trip to London this winter because this COVID is not going to get any better and I want to cancel to save more money to stay possibly 5 months. (Up to 6 months). I have 3 different people I know who are willing to allow me to stay and I like to book in advance this way plans don't get ruined such as on airbnb if someone else takes the spot during the time I am wanting to stay in UK. I know 2 people via airbnb 2 other people (1 a close friend and the other one a family friend) In fact I have 4 options but one of them is more expensive so I don't really know about that one, basically 3 options, but 4 honestly. Since I go to UK often, I heard US are allowed visa free up to 6 months but is that PER visit?