This is what I wrote when I went through my first heartbreak when I was just 14 (which explains why it might seem cringy). But as much as people joke, it's as potent then as it is at any age - especially as it's your first and it feels like it'll never end. But it will. And it does.
It just takes time and a whole lot of figuring out.
I never wrote about the real toxicness of our relationship. We were only young, it had to be a secret from my parents and he put an amazing strain on me - he was a drug-user, a mental-health denyer and honestly, he may've nice on the surface but deep down - he was rotten.
But I hope you can learn something from my process and at least find hope in it. After the initial heartbreak, I went on to live the best part of my life. Around 3 months after our break up, I realised I was the happiest I'd ever been. He wasn't everything. He wasn't anything at all in the long-run. You'll be okay.