The Context
Written by a man being betrayed
Psalm 55 isn't a calm devotional. David writes it while a close friend — someone he worshiped beside — is actively turning on him. He says his heart is in anguish, that he wishes he had wings so he could fly away and be done with all of it.
The word translated "burden" here can mean the lot you've been given — not just a bad week, but the whole weight of your situation. David's instruction isn't to shrink it, explain it, or manage it. It's to physically throw it onto someone stronger.
And the promise isn't that the problem disappears. It's that you will be sustained — held up under it — while God deals with what you never could.