가뜩이나 ~(으)ㄴ데/는데
as it is, already (and on top of that)
Example
가뜩이나 바쁜데 컴퓨터까지 고장 났어요.
I'm busy as it is, and now my computer's broken too.
Word parts
Probably related to 가득 'full' — already full of trouble.
Good to know
Almost always followed by -(으)ㄴ데/-는데 and then a complaint.