first name i've been using is different from birth certificate

Hi. I have been using Maria Amelia M. Abutin II as my name grade 6 onwards. I am now 35 years old. My passport, SSS ID, ITR, company, high school, college & training records, my son's birth certificate, my insurance, all use the same name. I learned that my name in my birth certificate is Maria Amelia M. Abutin (minus the suffix "II"). What are my options in correcting this -making my birth record to be Maria Amelia M. Abutin II?

I inquired at Caloocan City Hall and they said I can do an addendum. But my worry is that it's just the local registry and not in NSO. I am a single mom and concerned that my son may later on have problems claiming for my insurance, on his records, etc. We may live overseas also so I would very much like to make all my records correct and would like to continue using Maria Amelia M. Abutin II as my name. 'Hope you can help me on this.

-Mel

interesting question. sorry, i have to ask, but are you male or female? i know that maria should be female but i see in your username, it says mel, and your gender is relevant to answer your question.