I don't think I wanna make plans on my birthday.
Why do you not want to make plans for your birthday?
I feel like I'm just celebrating another month of slavery.
If you don't feel like celebrating your birthday, that is your prerogative. You don't have to do that if you aren't feeling like it this year.
I was just joking.
Be that as it may, just know that you can do whatever you want on your birthday. Don't feel obligated to have a party if you don't want one.