How to stop being sensitive?

I have been struggling with low self esteem for as long as I can remember. And now that I'm graduating, adult life is not very far away. I don't think it will get any better. I am very good at writing but when it comes to speaking I'm basically stuttering or not finding the right words. Many jobs include speaking with costumers and I don't think I will be able to do that. I already tried with a small job where i had to communicate with costumers and because of my trashy communication skills, I came off as rude (my co worker got mad at me and I had issues because of it, even if it was unintentional and I didn't mean to be rude) and got fired. I am really bad at many things no matter how hard I try. I try to understand things but I just can't. Sometimes I am very good at completing tasks but often I'm just dumb and slow. School is okay and I would do anything to stay here for another year. I am an overthinker and I hate doing mistakes (doesn't even make sense because i am chaotic and unorganized and lazy). I always get told to try to communicate more, but i have my family and friends, also i talk with many people and teachers at school with no problems. In public, at restaurants and especially in working places, it's very different. I'm a whole different person there. Okay, I am basically repeating everything i'm saying, which is useless so I'll stop here. Please I need tips on how to stop doing stupid things.
How to stop being sensitive?
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