Prohibited marriage in Hindu marriage act

My boyfriend and I are in relationship for 13 yrs now . We both are 27 and 31yrs . But problem here is both families are against our love due to prior conflicts between families. There is also another problem that we both are relatives and he is my cousin and this relationship comes under prohibited marriage act in Hindu marriage act . Will there be any issues legally at the time of registering the marriage? We are thinking to get married without parents consent in temple and register it .