I fumbled the sweetest person ever help me💔

So i broke up with my partner a few days ago and since doing tgat i've realized how much of them i actually took for granted. Idk what to do im just bawling my eyes out i hek miss her but i was an asshole to her bf we broke up ignoring her for 3 days tring to get myself together without asking for space i really fuvking miss her and her texts but i dont think she'd want me back bc like i said im an ass but she's gen the sweetest person ever and i felt i took her for vranted 100000% i rlly wanna talk to her but school starts soon and i have rlly bad anxiety i need tips on maybe how to let go?