It's not bad. Writing style shows that you have some skill with description and conversation. I do agree with NegiWarrior's comments. WAY too many switches in POV and even worse, you feel you have to tell the reader when it happens too. Probably because you know it otherwise would be confusing and hard to follow. Don't get me wrong, 90% of all the fanfic writers on HS have this same problem, even Kira has trouble with it.
Most of the time, with other fanfics when I read constant shifts of POV and telling the readers when it happens, its usually because the writers are essentially making it up as they go along. Those who have outlined plots and chapters planned ahead in advance generally do not have this problem. (I can think of Countess's and Slerotin's fanfics as examples off the top of my head, so my guess is that they probably are not making it up as they go along as much as other folks do.)
This is minor problem with fanfic though (since almost everyone does it), but if you ever get the urge to submit to real publishers, DON'T ever change POV unnecessarily or even worse tell the reader that you are doing so. No legit editor would stand for it.