There is one who speaks rashly like the thrusts of a sword, But the tongue of the wise brings healing.
Proverbs 12:18 (NASB)
Brood on Proverbs 12:18 by praying in the Spirit while holding that Bible verse in mind.
Also, repeat these meditatively throughout the day:
I AM WISE, AND MY TONGUE BRINGS HEALING. I SPEAK LIFE BY THE POWER OF THE HOLY SPIRIT. I OPEN MY MOUTH WITH WISDOM.