I've always thought that Moiraine's return would help Rand let go of his guilt and that list of women in his head. In his POV's, Rand has mentioned several times how grateful he is for Moiraine's help. He didn't realize how much she was helping him to BE the Dragon Reborn until she was gone. I think he also wants/needs to apologize to her and to thank her. All of these things will help him to be a better person who is lighter and less morbid and depressed.