YOU SAID:
happy birthday myself
INTO JAPANESE
私自身お誕生日おめでとう
BACK INTO ENGLISH
happy birthday to myself
INTO JAPANESE
私に誕生日おめでとう
BACK INTO ENGLISH
happy birthday to me
INTO JAPANESE
お誕生日おめでとう
BACK INTO ENGLISH
happy birthday
INTO JAPANESE
お誕生日おめでとう
BACK INTO ENGLISH
happy birthday
That didn't even make that much sense in English.