If you meet a guy that lectures you about “loving yourself” stay away from him. Chances are he is a user, especially if he is saying this to you after you are already having sex with him. Any time a guy says this to me I think, if I loved myself maybe I wouldn’t choose someone like you to date.
However, I should clarify that not every guy who says this to a woman is one who is a “bad” person. He could just really be trying to help even though that’s not really his place.
If he is overall a nice guy that seems as interested in you as a person as he is in getting laid, you can overlook the “loving yourself” lecture somewhat. You can even politely ask him to let you run your own life and make your own decisions and/or tell him politely that he can’t tell you what do to, and if he’s a nice person he will respect you.
On the other hand, if he has a history of seducing women with his kind words and sweet lies to get women in bed-and you know it-he’s the plague! Run women run! (That is, run if you don’t want to be used but if you don’t mind being used that’s your choice too.)
If he wants to play the role of counselor to you by telling you that you need to love yourself then chances are he probably doesn’t think that highly of you. If you try to discuss the fact that you are happy with yourself and he still doesn’t accept you for who you are suggestion is to dump him in a flash .
Then, I’d find someone who likes you or loves you for who you are. Either that or maybe you should be single for awhile and work on your self-esteem so you no longer have to deal with overly-critical men like this.