I get so angry and annoyed when my gf messes up.
Why exactly are you annoyed? How do you feel?
I feel angry and annoyed because she's not capable of understanding my feelings
You should have more patience with your partner if they have difficulty understanding your feelings. If you have trouble communicating with them then your relationship will suffer. Try explaining in it a way she can understand.
Why do I need to since I know how I feel.
She needs to know how you feel, but say it kindly, she cant read minds. If you love her you should have patients and try to give her the space to be herself.