Asking for Advice : What are the Grounds for Legal Separation under civil wedding?

Gdpm Sir,

I got married 2008 under civil wedding, after two years i went to work abroad as OFW from 2010 to 2013. only 2years with my wife physically together we have a one child, but for that two years that we have we have lots of misunderstanding, even before i went abroad last 2010 we are not ok. for the 3 yr's that i'm also working abroad me and my wife are not having good communication to one another. Since we are married under civil wedding( by Holy Sacrament International Church).  Can i file a legal separation, we got married but we are not members of the Holy Sacrament Int. Church? are this grounds for nullity of our marriage from the start?

Tnx Mark.

it can be, if it can be proven that both of you believed that the solemnizing officer had no authority at the time of the wedding. not easy though.