you need to train yourself to come more slowly. the way you can achieve that is to learn through either her masturbating you or having intercourse with you until you are close then stopping completely and then resuming when the urge to ejaculate has passed. this takes time and practice but that's not so bad right? in the meanwhile you need to be certain your partner is sexually satisfied in some way so i hope you are either masturbating her to orgasm or giving her oral sex to orgasm. i think if she feels sexually satisfied by you she will continue to work with you on this issue. .
could my daily masturbatoin be contributing to my premature ejaculation?