I missed an appointment today, any advice to "get over it" ?

I had an appointment at the hairdresser's but i missed it because i hadn't noted the right time. And feel soo bad ever since. The hairdresser called but it was too late so now i don't have an appointment. It ruined my whole day. First, my parents were mad at me and never stop remind me of it all day long. Then, I feel bad for the hairdresser cause she lost one hour and i'm so scared for when i'm gonna go next time, i'll don't know how to react, if she's gonna be mad at me or if i need to apologize even if they might forget about it. I'm so scared to take go back in the hair salon. As my plans changed, I wasn't able to do anything today and now i have tons of work to do. And now my hair doesn't look as i thought it would and i think i'll need to wait a while before getting a new haircut. I don't know why but i've been crying about it all day and it's so annoying : it's just an appointment it doesn't matter! But i can't help it. Sorry for bothering you with that but i needed to talk about it and if it happened to you i would like to know how you handled it. Thank you for your time