Where can it be defined as self murder?
You’re giving me an application of a principle that you believe valid, but not backing it up Scrioturally.
I have no idea what you don't understand.
Suicide is still the killing of a human being.
If you kill yourself THAT is still murder.
And THAT is in the Ten Commandments and THAT is in the Bible which is considered Scripture.
The principle: God is the Lord and Giver of Life. (= not you.)
The principle: Your body belongs to God. (= not yourself.) The principle: in Deuteronomy 30:19 God commands "Choose Life" -- and the rest of that command is, "... that you and your children might live." (=He's talking about you. You. And your children.)
When dealing with principles, the tech details don't matter. ("Do not shed innocent blood, it is an abomination" does not mean "... so, hey go for carbon monoxide inhalation, food poisoning or asphyxiation instead.")
Trying to avoid the inescapable conclusion of "Suicide is wrong" is like the so-called Gay Christians saying "Well, Jesus Himself never explicitly came out against anal intercourse, so there's that, Plus, St. Paul was talking about temple boy prostitutes, and we don't do it at a temple. We do it at the interstate rest stop. So that doesn't apply to us."