About the parental control issue, it exists to be used but it sounds like it's been a long while since you had a proper talk. Regarding your habits, I know "effort" sounds like a big deal but to the point of of showering only once per week or eating less without a reason... it's not only unhealthy on the short term, since you're on your growing period it will affect you for life. I don't want to take the role of your parents but, besides talking to them about all your worries, you need to build good life habits and set goals, otherwise you'll be dragged by other's whims.
[now i have to use my funky other browser, fuck you]