That's a heck of a position to be in, and one that isn't always the most comfortable. Like pennies, even the little things can add up and just become too much. I know it's going to sound cliched, but we need something to call our own; something that makes us happy, and helps us relax. Adults can burn out easily at work, but are often blind to how the system is built for kids now -- it can be overwhelming, stressful, and hard on morale and mental health.
Highschool is one of the best time that we can have -- or at least it should be. We should have fun, we should laugh, and we should be kids. Again, that's something that has been pushed out by parents who simply want us to excel at what we're doing. It's a hard go, but it can be dealt with.
I'm glad to hear that things are good at school; when you're an outsider there as well, things can go from bad to worse. Even though it's all girls, be sure to take the time to interact, laugh and have fun. This is so important.
As for the other things, might I suggest the following: Talk to your parents; let them know what's really going on and WHY you're feeling the way you do. Kids have way too much pressure now a days, and I can promise you that we'll burn out with present circumstances. I apologize ahead of time if I'm off the mark - and for the record, I'm half Chinese - but I find that parents from other countries are often a little harder on their kids in country. Expectations are different because of cultural norms.
I understand your father's aprehesions to let you date right now; he wants your focus on school, and probably knows what little terrors we can be. I'm sure your father is used to girls dating later in life, but things are different. I have found that the age gap is the worst thing to deal with, because expectations can be totally different. Again, you need to calmly chat with your parents. Listen to what they have to say, and don't blow up on them. They just need to understand, and you need to find a compromise with these things.
Life is too short, and you have plenty of time to stress, and work through life. Now is the time where you don't have to worry as much. Sadly, you're right at the apex of highschool where marks are crucial - as I'm sure they want you to go to an excellent school (all that love :)) - so there will be a LITTLE less time for fun...
But it doesn't mean you can't have any.
Take the time to think about what makes you happy. Be it sports, a hobby, or simply listening to music, dancing when no one is looking, or anything else. YOU need to make that time for YOU. It sounds insane, but finding out what you enjoy - and what makes you happy - can be difficult at times, especially when you're out of practice. So like homework, I want you to really think about it, and figure it out. Do everything you can until you find it, because we all have it.
But you have to make that time for you. I know it may not seem like it, but you have a ton of control, without going against what is 'expected' of you. It's your life after all, and being happy is paramount to success. Trust me on this one.
Take things little by little, and set little goals. Again, I know that sounds a little nutty - especially since we're trying to lighten the load - but it'll help with the little victories. Talk to your parents and let them know WHY you're feeling the way you do, and WHY you need to lighten things up a little. Don't demand anything, but ask for their feedback. Give them a big hug. Trust me on that one. And find that activity that makes you happy, or lets up on the stress. Even if you can only fit in 15 minutes a day, start with that. There are a few activities that you can really squeeze in with a little time, and the ones that are 'physical' can do wonders: Dance party, yoga, a quick workout, a run, or skipping. I LOVE skipping. ha ha.
One thing that works with parents that want structure can be sports -- it helps when applying to Uni too. I have been in martial arts since I was a kid, and train twice a week. Just make sure that whatever you do, is something that YOU truly enjoy.
I know words seldom solve the bigger picture, but I hope to have given you some ideas. If you want to chat, please feel free to message me. Chin up -- always.