First what's the reason for your overthinking?
Think just one issue at a time. Don't waste your time thinking on things you can't change. Trust God and trust His heart. Wait on Him. He's never early never late.

Watch movies and video clips that make you laugh. Stop from thinking too much before you sleep. Let your mind go blank and just close your eyes. Listen to good music. Eat food that will make you happy. You don't want to have wrinkles all around your face.

Stay positive. People don't want to be associated with pessimistic individual. Hope that helps.