Freudian psychotherapy

Kiki is an $18$‍-year old freshman who has been having trouble adjusting to life at college. After repeated incidents with her roommate, in which she screams at her roommate without any real reason or explanation snapping at her roommate without any real reason or explanation, Kiki is referred to counseling. At her college’s counseling center Kiki is assigned to a psychotherapist, Dr. Sigmund, who operates from a psychoanalytic framework in his treatment sessions. Dr. Sigmund asks Kiki to tell him about her childhood. The following excerpt is from the recording of their session:

“When I was born, my mother didn’t really want to breastfeed me. She resented the fact that she had to breastfeed and only nursed me for ten months. I guess I had a normal childhood, other than that resentment my family members clearly loved each other and everyone has always been kind to me. It doesn’t really make sense, but I became a really tough kid…I’ve always been really sarcastic with my friends and family. I feel like I need to hide my true self from everyone around me, like if they knew the true me then they wouldn’t love me anymore. It makes me anxious. Maybe that’s why I started smoking when I was little. Anyways, when I came to college I thought things would be different, but I really miss my family and I feel really homesick. Whenever I try to talk to my mom about it we end up fighting. Now that I think about it, that’s probably why I’ve been snapping at my roommate.”

Dr. Sigmund tells Kiki that he believes the relationship she had with her mother when she was an infant had a profound effect on the development of her personality.

According to Freudian theory, during which psychosexual stage did Kiki experience strong conflict?