Sounds like your parents (dad in particular) are being passive-aggressive, most likely as a result of coming out to them. They can't change you so they'll do their best to try to control you. Time to start making a plan to move out. If my parents were monitoring my hygiene, bedtime and comings-and-goings at 19 I'd tell politely to mind their own business. This has nothing to do with "our house, our rules" - they're don't want to let you grow up and can't come to grips with the fact you have. Do be considerate after their bedtime - nothing more irritating that someone rattling around the house when you need to go to work the next day. If that's the main reason they want lights out at the same time I can understand that - I'm a light sleeper and oftentimes people being up after I go to bed will keep me awake (even if they try to be quiet).
This post has some very sound thinking.
Is part of the reason they are treating you like a child related to your behavior - as in perhaps behaving like a child the past few years. Not meaning that as an insult, but from a parental point of view, perhaps you had a run of behavior that scared the bejeebus out of your parents, but is also making them still see you as a child. So to my thinking, the best course of action, since the "just move out" response is wildly impractical to put in place just like that, is to sit down with your parents and, well, negotiate. It sounds like you can't afford to move out right now, which happens, no big deal. But I can also understand you chafing under some parental rules at nineteen, that were acceptable at, say, 14.
If you need to, acknowledge issues from the past, but explain some changes you would like - and perhaps, to show them maturity and thoughtfulness, offer up some help in return. Do they need help around the house - whether it's repainting some rooms over the summer, a lawn work schedule or something, and explain that you would like them to back off giving you a bedtime. It doesn't sound like you are out running with a bad crowd, but if you want to stay up late and play games or something, tell them you will use headphones and be quiet so as not to disturb them, etc. I am just tossing out ideas but the bottom like, try to help them see you as more mature and responsible these days and hope that they will back off treating you like you are much younger.
Edit - I removed a few random, pointless posts that did not appear to have anything to actually do with the topic. I know there are a few more in the thread, but... I have to go to work.