Breakup Survival Guide
I love the title of Alison James' book in the resources section. It's called " I Used to Miss Him... But My Aim Is Improving.
But really, her 48 hour rule is the best advice. Step away from the email, phone, computer and resist sending any notes, messages, videos... for at least 48 hours after a break up. You need to give your emotions some time to settle and your brain some time to process.