@kimsoo522,
I can tell you in the first sentence that you'll need to rethink this.
Of course the admissions committee has intelligent people on it, but you're not doing yourself any favors by throwing out terms like dismay and vacate. I'm not saying to dumb it down but the verbiage just looks pretentious from here.
Also, lots of people have heartaches during their college years. I don't think the admissions committee wants to hear it. What good does it do to mention it? Unless you are trying to provide a reason for subpar grades (and even then, no, it's not likely to work as an excuse), leave it out of your essay. Yes, it's a personal hardship (and it did cause you to leave one school), but they're talking about stuff more like caring for a sick relative or your mother dying or you getting into a car accident and rehabbing your leg for six months. It's unfortunate your fiancé and you didn't work out, but don't put that information into this essay. I would just write that you were depressed and had no personal support system.
Let's look at the requirements.
Academic history - how did you do in nursing school? Did you like any of your classes? Were any of them impossible? Did any of them give you the heads up that this wasn't what you wanted to do with the rest of your life? Explore those sorts of things in the essay.
Career goals - what do you think you'll do with your education? Sometimes the answer is just, you'll go onto more education.
Cultural understanding - your life changed radically when your family left Korea. Talk about that. But ditch terms like motherland and fatherland (a term that to a lot of people evokes Nazi Germany).
Challenges and personal hardships - consider how you aren't a native English speaker. The culture is extremely different from the country you were born in. You can weave these two elements together.
Fortunately, the essay requirements are pretty clear. We so often get these essay requests and they are incredibly vague. This essay request is giving you the structure on a silver platter. Follow it.