Leave. If he did kill himself you could heave a sigh of relief and clean the blood up.
Actually these control freaks make you think you are not a good wife. Get a video and film hm next time he threatens then leave him to it.
The suicide prevention advocates say to always take threats of suicide seriously. But I've seen a feminist domestic violence model label threats of suicide as an 'abusive' behavior. A lot of normal male behavior can be interpreted as abusive based on some of these models, btw.
I think it is probably wiser to follow the suicide prevention folks' advice and take it seriously. Threatening suicide is not a sign of being in a good mental state, of course. If someone does this as a manipulation tactic, that's a bad thing, but it is quite likely someone who threatens that is not in a good mental frame of mind and not just trying to manipulate the other person.
If husband and wife are both living right before the Lord from their youth, then they marry once. The husband loves his wife as Christ loves the church and honors her. The wife submits to her husband and reverences/fears/respects him. If there is a disagreement, between the love and submission, it does not turn into a fight. He loves her and seeks what is best for her, and she is willing to submit to his decisions. If he honors her and she reveres him, that rules out cursing each other, throwing plates, screaming at each other, etc. If both are walking with the Lord and walking in the Spirit, then they don't divorce or threaten to divorce because both are faithful to the Lord to follow his commands such as 'let not the wife depart from her husband' and 'let not the husband put away his wife.'
Where it breaks down is where one or both sin, err, aren't following what the word of God teaches. If a husband and wife are walking with the Lord, they can make it work. If one has said hurtful words and hurt the other, he or she can humble himself or herself and ask forgiveness. And the other forgives, because Christ taught us to forgive.
My wife and I have been together for 20 years, but we have gone through some periods of time when we have argued, usually involving stressors like moving, giving birth or caring for a young baby, staying for an extended time with parents, living in a foreign country, her having PMS, her having post-partum blues, or a combination of all or most at the same time. We've gotten into what Eggerichs in his book 'Love and Respect' calls the crazy cycle. That's where she says something he perceives as disrespectful so he says something she percieves as unloving, and it creates a cycle of not getting along.
When it got really bad, I'd just ask my wife to go through a time of prayer with me where we humble ourselves, confess our own wrongdoings without 'confessing' the others and ask forgiveness and pray to God to help us, reveal any sins so we can confess them, etc. It has gotten us out of that cycle where your partner takes every little word as if it was intended to start an argument. Forgiving and letting the Lord heal allows the feelings of love to return to the marriage.
My wife, during post partum blues and bad PMS arguments has thrown out the word 'divorce' a few times in arguments during our marriage. That seems to have mellowed with age and maturity. But I have never threatened her with divorce. I'm the head, and if I agreed with her, it could have disastrous consequences. Divorce isn't in the consideration set for me. If we are having a disagreement, I am having a disagreement with someone I love who I have committed to be married to for the rest of my life, and I know God expects that of me.