Yes, I am under 21 but my dad is not a citizen yet, he just holds a greencard. Can the I-485 be still be filed?
OK, I should have that question too.
No, if your father is "just" a GC holder, you are basically hosed. You will have to wait till a visa number becomes available for you, which is a multiple year thing, and you won't be able to wait in the US for that.
Currently in your category they are handling applications filed in June of 2004. So, it is probably before then that your dad can apply for citizenship and then ammend your application, which will speed the process from that point onwards.
Again: you will HAVE to leave the country. Not just because the family emergency, not just because you didn't register for classes, but mainly because your father filed I-130 for you.
Hindsight always being 20/20, it was a very bad move to file I-130 for you, while your father was still on GC. If he would have simply waited until he became citizen, (a) you could have stayed in the country as F-1 student, and (b) it would not have delayed your getting GC.
Your only option now will be - after you have handled your family emergency - to try to return to the US under some kind of work visa. But with your study interrupted and the current state of the economy....
It would be very ill-adviced to marry just to get a GC, but... if you do have a US-citizen girlfriend and are close to getting married anyway....
Wd