I feel like i'm bad at my job!!! what should i do?

-ok so i recently started working at a pizza place. my first day of training was june 26 and i have worked about 10 times since then. i just feel like i'm doing so bad. my manager put me on phones and i'm not that experienced so when both phone lines are ringing off the hook it gets overwhelming at times and my boss tells me to just do the register. so i really hope i get better as i get more experienced but i'm just nervous because my boss is about to fire one girl who has been working here for 3 months because she still isn't the best at phones! i'm sooooo scared that i am going to get fired and that my boss isn't impressed. i could give two shits what my manager thinks because she never has anything nice to say. but her rude, 'wise' comments still hurt my feelings and when i go home all i think about is work and all of the negative feedback i've gotten. what is the best way to get those rude comments out of my head??? work is consuming my thoughts! please help me!!!Just don't let them get to your head. A lot of people that feel like they have authority over others use that to their advantage and abuse their position. If you try your hardest, and only get negative feedback...well then that's wrong. You've not worked that much at all, especially since June?? That's ridiculous. I always get put down at my job too, and I've been trying my HARDEST not to let it get to my head. I agree it can be difficult. But now that I've started to not give a **** about what they say to me, and just do my job as I know I'm supposed to...they've stopped harassing me. Trust me, honey..this isn't going to be the only job you have in your life (: You'll find that one job you absolutely love. Until then, just try your hardest, and don't let anything they say get to you. They're just being bitchy...they should know how hard it was for them when they started out. They're just immature.If 2 phones are ringing at the same time, he doesn't expect you to answer both simultaneously :) Just grab one and ask if they can please hold, mute it then grab the other.
I'm surprised you haven't got fired yet.
It's only pizza, I wouldn't worry about it. It's not really a job you want to spend your life doing.