How do you get over a breakup?

I’m begging for him to fix things between us

I’m so miserable, sad, depressed, and heartbroken, he said hes done for good...he said he doesn’t want to be with me, he said he doesn’t want to give us another chance

I’ve been begging him to fix things between us since Friday

I’m desperately texting him, begging him, he won’t give us a chance to actually talk things out

He won’t give us a chance to both change our ways to improve our relationship...he’s done..he stopped texting back, he won’t answer my call (only called once)

Please how do I get over this...I’m so sad...I’m miserable..things weren’t supposed to turn out like this....he was my first love, I can’t bear the thought of not having him in my life, I don’t want to think about never kissing, hugging, smelling or touching him again

We also work together so I feel like this may be harder to get over, I don’t want to quit...It’s going to hurt me so bad to see him flirt with other females at work, I can’t imagine seeing him with someone else..that hurts so bad..

(& I’m 18 since some may ask about age)