It is a difficult situation.

Not sure why your parents let their daughter get away with most things, and their attitude towards you. Likewise, hard to know why your other siblings aren't helpful. There is no easy answer.

Would it help to have a meeting with all your siblings and telling them to share the caring for *their* parents as well?

As for your moving or not. I'm afraid only you can answer... You do need to take care of yourself. But from what you write you seem to be rather dedicated, and as you say "protective" of your parents... so would you be able to live relatively far without feeling guilty about it (knowing your siblings aren't going to be as caring)?

I am not suggesting you move or stay, as it is understandably quite hard for you to shoulder all the responsibility. And your siblings/parents should not expect you to do that.

However, you do need to consider all the options/implications and if you basically could live with whatever choice you make. And go on from there.