It sounds as though whatever mental process you went through, you managed to embrace both your insignificance and your mortality. That’s a good thing, in spite of the circumstances.
You let go, and in letting go, you stumbled into some enlightenment. It should be said, though — the peace you’re experiencing is a manifestation of life, not death. You’ve been given a gift. Spend some time with this new mental state. Explore it. Learn from it. Don’t waste it by actually killing yourself.
You can let go without giving up.