Edit: Thought I’d add some thoughts I had that kept me going since I assume you’re going through your first right now?
1) all those things you two enjoyed together are just things. They’re objective. What I mean by that is that if you frequented X restaurant or she introduced you to Y band, they’re not “hers”. The restaurant and band don’t give a shit about her -they may even dislike her if they met her- so enjoy the things and places you enjoy. A park is a park, a shirt is a shirt, and so on.
2) you are a fucking king, man. I used to tell myself that well, if I ever run into her again I want her damn jaw to drop cuz I’m killin it across the board. As I saw here on reddit once, “this is your game of life, be the best you can be”
3) I was an immature fuck when I went thru my first breakup. Still am, probably, but I know I’ve grown a lot since then. I might even be a man now, who knows. But as I watched myself change (and I changed basically everything) I started to get really excited to see how a new and more mature relationship would be. I mean when k really think about it, it’s gonna be a whole new experience. And this time I wont be a codependent pussy! Cool!
4) holy shit look at how much more money I have! For the first few months I would take what I figured I used to spend on her in a month and then go treat myself. New shoes one month, new jacket next, etc. It’s fun to date yourself. And honestly it’s fun to be selfish.