Dont know if i should marry my gf in the future?

ok so my gf and i have been dating for almost 5 months, we are both in high school, and i have a major conflict in my mind. let me explain my problem, my gf is southern baptist and i am roman catholic, she is a religious nut and im not, now dont get me wrong i love her but religion is not the problem our parents r. her parents r ok with me and her dating but my parents arnt. my parents think her parents r crazy and weird ( which i believe as well ) my parents r constanly asking me when im going to dump her and i normally dont listen to them, for 5 months i have thought that i would marry my girl friend but today my dad said that if i marry her he will disown me (not in a literal way but u know what i mean) now i dont know what to do, should i listen to my parents and dump her to make them happy and potentionaly find someone better or stay with her and make my parents angry? please help with suggestions, has anyone else had this problem?