Quick answer
Rage is bad and jealousy is worse. The verse ends in a question because it does not think there is an answer.
Read both lines
The first line stacks two serious things, cruelty and a flood, both of which describe force arriving from outside and passing through. A torrent is survivable in one respect that matters: it goes somewhere. It arrives, does damage, and drains.
Jealousy is the second line's subject and the reason it is worse is that it does not drain. The verse does not explain this; it asks a rhetorical question and lets the reader supply the experience. Stand before is military language, the posture of holding a position against an assault, and the implied answer is nobody. What the verse has noticed is that jealousy is patient in a way anger is not, and patience is what makes it unanswerable.
Related: Proverbs 6:34 · Proverbs 14:30 · Song of Songs 8:6 · Proverbs 27:3
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.