Typical therapy involves assessing the situation and approaching it to better understand what is wrong.
Now, I ask you again. What is your character going for?
Most therapist try to show the patient what may be wrong. They understand what is wrong and how to solve it, but its the job to make the patient reveal that and find a way to solve it. Lets say a person had control issues, that they constantly want to be in control of others. The therapist will speak with the person, not trying to focus on a subject, but just understand the person better. They will raise certain question based on observation. Like the patient walked into the room and told the therapist to close the door quickly before the chill would come in. The therapist would ask, "Why did you tell me to close the door?" The patient: "Well, you we're closing it fast enough." "I was about to close it. And, either way, it took more time to tell me to close it and have me figure it out and finally do it." "Well, yes but--" "What do think I'm feeling when you're telling me that?" "I don't know." "No, what do you think I'm feeling when you order me around?" "Ah... angry. Whatever, can we get on--" "If I get angry, do you think I like being ordered around?" "No." "Would you like being ordered around in the same way?" "No." "So why order people around like that?"
A therapist takes several different methods to have the person understand what is going on. The above, I used simple reflection from a different point of view and mirrored it back. You want the person to talk about something that is bothering them, and from your neutral point of view, bring them something that they can look into and figure out. You want to lead the individual down a path, but not direct them, but give them clues.
Typical therapy takes a long time. It's not about walking in and getting that mental problem fixed. It's about constant support, understanding, assessing and evaluating.
I don't think one on one therapy is good for a book in a realistic stand point. But I wouldn't know, I had no damn clue what therapy your character needs. So tell me.