I mean it. Delete her number from your phone. Hide her posts on Facebook. Don’t call her, don’t text her, don’t hang out with her, and whatever you do, don’t try to stay friends with her. All that’s going to do is fuck your mind up even further.
Instead, throw yourself into your hobbies. Plus, take up at least one thing that will better you. If you don’t go to the gym, go! If you do go to the gym, go more! Eat better! Read books! Be better!
And still don’t contact your ex. She’s dead to you, remember?
Eventually, you’re going to wake up one morning and feel better than you did the day before. That’s going to string together, and you’ll start to feel better and better without even knowing why.
Plus, you’ll be improving your health, and doing the things you love doing, and putting yourself out there in new situations with people, and eventually, Howard, you’ll be over her.