Do NOT cut or do coke. Don't do anything that you wouldn't do if you were 100% normal (happy wise.) This could leave you feeling regret or guilt. Someone like her isn't worth your tears or your blood.. Do something time consuming like taking a walk while listening to music, calming music. Ask your buddies to come shoot hoops with you. Do anything that occupies the brain and isn't harmful. I would tell your ex-girlfriend that you need 2 weeks to a month of no talking to get over everything. Hope everything works out for you.