What you said is spot on. Harry doesn’t have a good relationship with his family. And what he desperately wants is to be as important as Will. He picked someone who he thought would help him “change the world.” Hence giving him the sense of importance he’s always craved. When what he needed instead was a good therapist. Someone who could help him recognize that he has an extraordinary life. But nope. He went the D-list actress route. He’s an idiot.