He suffers from the same frailties and hormonal-related problems as all sorts of people his age, but he's also going through this massive thing of almost paranoia, where someone's trying to get at him, trying to destroy his life, but he doesn't know who. Some invisible force is trying to tamper with his life in some way.
As you grow up, you realize from the age of 14 or so, you grow extra emotions somehow, and I think Harry is at the point where he's at the mercy of all these emotions,