Nice translation. If you don't mind, I'd like to point out one thing:
どうでも良い means something like "I don't care". Like どうでもいい話 or 私はもうそんなことはどうでも良くなった.
(
Definition: 価値がない、どっち決まっても良い、あまり興味が無い、といった意味の言い回し。Other examples
here.)
I think that made the thirsty/hunger part difficult for you to interpret. I interpreted it as: after my mind hit rock bottom and felt numb, my body started craving for water (life) again. Maybe in the future, I might even feel alive enough to crave food as well.
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The lyrics are so heartbreaking, I couldn't help but make my own translation too:
Diary
This is just my diary
I don’t mind if my words don’t reach anyone
Nobody would notice anyway
and even if they did, they wouldn’t care,
they’re too busy with themselves
Telling me not to act
as if morning will never come again
as if the sun will never shine on me again
*
Why did you die?
Why did you…?
Why am I living
in a world without you?
When everything had turned to nothing
and I didn’t care about anything anymore
I felt thirsty and craved water
I wonder if I’d feel hungry and satisfy my hunger
like I would’ve done in the past
if I’d wake up at some time
**
She told me, "Important things
are harder to protect"
She told me, "If it’s you,
you can protect them for me"
* repeat
** repeat
This is just my diary