null and void?

good day po sa lahat. isa po akong public school teacher at nakapangasawa ng lalaking dati na palang kasal na. on April 12, 2011 we got married dahil nakapagcomply naman ang lalaki ng mga requirements to marry at nanganak ako ng isang baby girl noong August 7, 2012. lingid po sa aking kaalaman ang lahat na yon. on November 9, 2012 pumutok ang balita na ang asawa ko ay kasal na pala dati noong April 25, 2009 kung saan mas una ang kasal nila kaysa sa amin. nachange na po ang civil status ko sa civil service commission noong Aug 3, 2012 bago pa ang scandalo. at mula noon hindi na kami nagsama ng iniasawa ko pero pinapayagan ko siya na makita at mabisita ang kanyang anak pero dahil doon nagalit at dinimanda ako ng una niyang asawa ng Administrative case at naging formal charge na ngayon. ano po ba ang dapat kong gawin? pwede po ba akong matanggal sa trabaho ko?

if it can be proven that you knew he was married prior to marrying him, then it can be a case of immorality; therefore, you should be preparing to answer the charge with your own evidence that you did not know he was married. also point out your actions when you did find out that he was in a prior marriage to show you were acting in good faith.