ただでさえ
even at the best of times, already (and now…)
ただでさえ A のに、B
Sign up free to review this point on a spaced schedule.
ただでさえ says that a situation is already difficult even in normal conditions, and then something makes it worse: ただでさえ忙しいのに、また仕事が増えた, "I'm busy enough as it is, and now I've got even more work".
The first half is a normal, ongoing state: busy, cramped, hot, short-staffed. The second half is an extra burden, and the tone is usually a complaint. のに and うえに often join the two halves.
It combines ただ ("ordinary, as it is") with でさえ ("even"). So the feeling is "even in the ordinary state it's X, so now…".
Compare いつも, which just says "always". ただでさえ adds "and now it's even worse".
Examples
ただでさえ忙しいのに、また仕事が増えた。
I'm busy enough as it is, and now I've got even more work.
ただでさえ狭い部屋に、大きなソファを置いた。
We put a big sofa in a room that was already cramped.
ただでさえ暑いのに、エアコンが壊れた。
It's hot enough already, and now the air conditioner's broken.
ただでさえ人手が足りないのに、二人も休んだ。
We're short-staffed at the best of times, and two people are off.
彼はただでさえ声が大きいのに、酔うともっとうるさくなる。
He's loud enough normally, and he gets even louder when he's drunk.