Please please please help i need all the advice i can get?

so my boyfrined got caught wiht porn somthing i feel really strongly about i am very much against and he kows that and for a whole year he went behind my back did it anyways, he promises he will never look at it again he seems to feel really bad about it the only way i know is from his recycle bin. but now i feel like he is still doing it i cant give him the trust i want to give casue he has lied before. we have only been dating for a year and in that year he has lied numerous times i had always constantly asked him if he liked and or looked at it he always said no. whats my next step. its bad casue i cant even tell when he lies or not.