I'm fine, thank you. It sounds like you're not, though.
Well, what's said is said. You can't unsay it. And in any case, it sounds to me like it needed to be said. It may not have happened at the best time, but at least it's out there now. From what you've said, it seems like you are trying your best to be a good daughter, and your father and mother are doing their best to be good parents. They shouldn't have been ragging on you about the small stuff when you were doing so much else... and you shouldn't have been trying to handle so much without letting on how hard it was. If your parents don't see how hard you're trying, how can they support you?
You could try going to them, letting them know that you love them and understand that they're trying to help you, to give you good advice and raise you to be a responsible person, but that you've been doing a lot lately--more than they know. And then you could try telling them why you're so stressed and ask for their support. (Support doesn't necessarily mean advice. Just knowing that someone understands the pressure you're under and is willing to listen can do a lot to relieve stress.) You'd better be ready to listen to them, too, by the way. Understanding has to go both ways for a good relationship. Supposing they won't listen to you, you listen to them. Try to figure them out. Once you understand how they think, how they feel, how they reason, it will be easier for you to get them to understand you.
I take it your parents are immigrants? That probably means their wish for you to succeed is tremendous. Immigrants tend to be amazing that way; they fight harder, work longer, and dream bigger than just about anybody else. :)
Dragontongue's advice sounds good to me. You might like to give that a try. I particularly like the idea that even if they still don't really see, hear, and understand you (which I know you would like), at least you will have seen them, heard them, and will understand more about them which you then can apply towards easing tensions.