St Anthony’s pretty good at finding lost things, so you can try this prayer:
St. Anthony, perfect imitator of Jesus, who received from God the special power of restoring lost things, grant that I may find what has been lost.
At least restore to me peace and tranquillity of mind, the loss of which has afflicted me even more than my material loss. To this favour, I ask another of you: that I may always remain in possession of the true good that is God. Let me rather lose all things than lose God, my supreme good. Let me never suffer the loss of my greatest treasure, eternal life with God. Amen.
St. Anthony, helper in all necessities, pray for us.