I think the best person to advise you on this topic is a qualified lawyer. As far as my knowledge is concerned, I can tell you that in most cases people have to go through a divorce to nullify their marriage. I think there is also a procedure where the marriage can be annulled by giving a "Nullify Petition". There are also some cases where the marriage gets automatically annulled.
Some of the examples where you can go for an annulment are when the marriage is not consummated, when one of the partners were married to somebody else, when one of the person in the marriage was under 16 during the time of marriage and when a partner might have had a sexually transmitted infection and was aware of it at the time of marriage but the other partner wasn't. As I said before all these clauses would be clear only when you contact a lawyer and get his guidance. He would also be able to instruct you on how to nullify the marriage but not be affected by it financially or in material terms.
Some of the examples where you can go for an annulment are when the marriage is not consummated, when one of the partners were married to somebody else, when one of the person in the marriage was under 16 during the time of marriage and when a partner might have had a sexually transmitted infection and was aware of it at the time of marriage but the other partner wasn't. As I said before all these clauses would be clear only when you contact a lawyer and get his guidance. He would also be able to instruct you on how to nullify the marriage but not be affected by it financially or in material terms.