NULLITY OF VOID MARRIAGE

Hi po! Eto po ang story ko, me and my partner met 5 years ago and we want to get married. But there is 1 big problem, he was married 18 years ago. 18 yrs. old po sya that time & 17 yrs. old yung girl. Pero finake po nila ang age nung girl para makasal sila sa church. Few months lang po sila nagsama and naghiwalay din agad, buntis yung babae. Hindi nakita ng partner ko yung anak nya until after 3 yrs. nagpakita yung girl dala yung anak. Iniwan sa partner ko yung bata. Never ng binalikan, nagparamdam or lahit tawag sa kanilang mag-ama. Hanggang sa magkakilala po kami and nagplan na magpakasal, declaration of death po sana nung dati nyang wife. Since wala pong nakakaalam kung asan na yung babae or kung san na nakatira. Then after 15 years, debut na ng daughter nila biglang nagpakita yung babae. Inaway ako and ang partner ko. Busy lang daw sya kaya sya nawala ng parang bula. We don't and we don't care about her story. Gusto lang po naming magpakasal ng partner ko since 5 years na kaming living happy together. Ask lang po namin kung magkaiba ba ang Nullity of Void Marriage and Annulment? And how much it will costs us? Thank you po.

Hindi po kami masyadong familiar sa mga.legal terms pero mas mabilis po ba kung ang gagamitin namin grounds e yung fake age ng girl on their wedding. And yung more than 4 consecutive years absentee?