What is Holden desperate for?

The answer to this question is not entirely straightforward as Holden seems desperate for quite a few things.
Holden is desperate for authenticity. He expresses his frustration with phony people and their phony behaviors throughout the entirety of the novel. Holden's sister Phoebe is special to him because she isn't phony at all, and perhaps it is her youth that prevents her from being this way.
Holden is also lonely, so he may be desperate for company, but not just any company. He is a rather discriminating character, which means that Holden is selective about his friends and whom he can trust, and people often let him down. Holden is desperate for real friendship and connection.
From an outsider's point of view, Holden might also be desperate for a good therapist who can talk his language and understand him for all of his emotionally intelligent complexity. Without a doubt, Holden has dealt with a lot of difficulty in his young life, between the death by leukemia of his beloved brother to being abused sexually by a trusted adult. His relationship with his parents is challenging and he acts out in worrying ways. He thinks about suicide. All of these reasons might lead someone who knows Holden well to think he desperately needs professional help.