Under any circumstances, is suicide allowed in Islam (under Quran-only Islam rather than Sunnism)
...not for the purpose of war or terrorism, but due to long term emotional suffering, pain and depression?

I'm having some trouble understanding the verses 429-30

429 ....And do not kill yourselves; God is Merciful towards you.
430 And whoever does so out of animosity and transgression,
we will cast him to a fire and this for God is very easy.

What if one's suicide was not out of animosity (i.e. to purposefully hurt somebody else) or transgression (being vengeful or angry at God for the current situation) ?

Please give your opinions and interpretations based on knowledge from the Quran.

Much appreciated,
God bless