He Has a Lust Problem

Recently my boyfriend told me he didn’t want to marry me yet because he has a lust problem which I’m not mad at him for and I understand because he recently cheated on me (not physically) but I just can’t get it out my head and I feel like something wrong with me and I do everything Litterally brought him whatever he wanted (he don’t ask) I cook breakfast and dinner DAILY and sexually I Always do MY job ! But I just feel so low everyday because why does he have this problem I just want Postive vibes and advice please