What does the Bible say about anxiety?

In nothing be anxious, but in everything, by prayer and petition with thanksgiving, let your requests be made known to God.

And the peace of God, which surpasses all understanding, will guard your hearts and your thoughts in Christ Jesus.

casting all your worries on him, because he cares for you.

Don’t you be afraid, for I am with you. Don’t be dismayed, for I am your God. I will strengthen you. Yes, I will help you. Yes, I will uphold you with the right hand of my righteousness.