I'm going to forget my girlfriends birthday due to being tired and stressed out
Why would you forget your girlfriend's birthday?
She always makes fun of me and she acts real annoying.
Birthdays are meant to be a time of celebration and happiness. I think it'd be really important to her that you remembered the date.
I really hate even acknowledging her.
It sounds like maybe you aren't very invested in this relationship. Perhaps you consider ending things if that's the case.