Anxiety can be very crippling to a person. It can lead to negative thoughts and depression. Here is a dua to remove anxiety. It is reported in the Hadith Sahih Muslim 592.
Aisha reported: When the Messenger of Allah, peace and blessings be upon him, finished his prayer, he would not sit long enough but to say, “O Allah, you are peace and from you is peace. Blessed are you, the Majestic and the Noble.”
“Allahumma Anta Salam, wa Minka Salam, Tabarakta Yaa Dhal Jalali Wal Ikraam.”