sorry he is cheated me a lot.. but he is saying that "he never cheated me" .. he used to say everytime that he dont want to act as perfect one.. He says"he born in good family so he will never cheat me"..

He is using mobile without my knowledge. i came to know that few days back.. even i asked him he saying same(i will never want to cheat you)..he makes me fool.. he saying that " you are psycho so only you are getting this kind of thoughts"... what i should do? i know he is really cheating me and talking with some other girls.. he is womaniser i think.. i dont know whether i am thinking like that ... please help me.. give me more suggestion.. my parents are getting ready for us marriage i dont want to live with this person.. i want a person who loving me more and more.. who cares me more than i expected.. really i am felling like despondency...