Why do you have to do this? Breaking up doesn't mean you have to be alone. When you are sad, go find a friend and talk to him/her. You will feel much better. Don't always fight the loneliness by yourself. Especially on your birthday, give yourself a holiday, relax and have a carnival with your friends.
Forget those sad things. Friends will also give you a lot of birthday gifts. Of course, you can also have a happy birthday and give yourself a gift. Reward yourself for being strong and be creative. Nothing can make you lose the right to be happy. Order a real doll for yourself and make it cute. You can also give yourself a 925 silver name necklace made of your own name, or buy yourself a big plush doll to accompany yourself.
Haha, everything is up to you. Be happy. Everything is floating clouds. Only happiness is the most real.