If you mean it as confessing to someone. An intimate love. I'm aware you use 'aishiteru'. But with confessions I've heard people use 'daisuki' instead which is more 'really like'. Suki - like Daisuki - really like/ love Kirai - hate Daikirai - really hate Suki jyanai - dislike. You can say hontouni kirai for a more literal translation of 'really hate'. Same for really like. Daisuki and daikirai are just deeper feelings of like and hate.