If you really love her, you should help her in her lows instead of giving up on her. In the end, if you don't help/love her at her worst you don't deserve her at her best.
Can she do the English exam test again and apply for the same masters next year? If so, you should spend some time teaching her English.
If you want something, give it.
You want her to show more affection and attention? Do it first, buy her flowers, her favorite candy, surprise her with a dinner when she comes back form work, whatever would make her smile.
Keep doing that for at least a month, then either of these 2 things will happen:
1- She'll show the same affection and attention back. In this case, congratulations :)
2- She'll stay the same(I hope not). Now, you've done your best as a boyfriend to fix the cold relationship. You are free to keep trying and amp up the effort, or break up. And if you chose to break up now, you shouldn't feel guilty or responsible for anything that'll happen to her after you leave her.
Look, in the month or so timeframe, you should REALLY do your best. Do it genuinely while believing it's gonna work, and don't do it with the attitude of "meh" or "whatever".
Also, since she brought up wishing to be dead when you talked to her about break up, it means one of two things:
1- She's depressed, perhaps suicidal.
2- She's being manipulative, and uses death to scare you away from breaking up.
From my position, I can't really tell which one is true. Sit down for a bit and think about it, did she say that because she's depressed or manipulative? And act accordingly.
Wishing the best for both of you.