Obsessed?
I think every character shrine has a page like this, something like "You know you like [character name] too much when..."  Well, this is my list, and if you have any contributions that haven't been added yet, email me.

You know you should get over Cedric Diggory when...
1. You pretend to play Quidditch with a yellow sheet draped over you.
2. You took a Sorting Hat test and you were upset when you didn't get sorted into Hufflepuff.
3. So you go back and alter your answers so that you'll get into Hufflepuff.
4. You wish you were Cho Chang, for obvious reasons... *wink*
5. Yellow (Hufflepuff House's color) is the ONLY color you wear.
6. You get gray contacts, even though you don't know how to put them in
7. You cut your hair like Cedric's on the front cover (extra points if you do this and you're a girl)
8. You wear black for two weeks after finding out that Cedric died.
9. When you wear black and people jokingly ask you, "Hey, who died?" you say "I'd tell you, but that would ruin the ending of the book." (this actually happened to me, and that's what I said ^-^)
10. You look up people named Peter Pettigrew or Tom Riddle in the phone book and call them up and yell at them for killing Cedric.
11. You try to send a Howler to these people
12. And it actually works
13. Whenever you are being attacked, you try to transfigure a rock into a dog to distract your attacker.
14. Whenever you go swimming, you try to do the Bubble-Head Charm.
15. You start to think of songs that remind you of Cedric and you cry whenever you hear them (I used to do this...once "With Arms Wide Open" by Creed came on in the car and I started crying and Mom looked at me like I was nuts.  Which I am.  But that's beside the point.)
16. You contact the company who makes the Harry Potter merchandise and insist they make lots of Cedric stuff
17. You try to sculpt a miniature model of a Swedish Short-Snout like the one Cedric pulled from the bag at the first task
18. Your favorite animal is now a beaver.
19. For your next school dance you ask out a girl who looks like Cho and you wear robes and insist she do the same, or if you're a girl you cut your hair like Cho and you wear robes and try to find a guy with brown hair and gray eyes who looks like Cedric and get him to take you.
20. Whenever Cedric got hurt in the book, you felt as if you were suffering just as much (especially when Krum used the Cruciatus Curse on him)
21. You found yourself rooting for Cedric the whole time instead of Harry, and you wanted him to win the cup instead (wait...but then he'd be the one to ressurect Voldemort, isn't that right?  So then he'd still be killed?  Uh...damn.)
22. You tell people that the reason you didn't cry when reading the book is because your grief "is beyond tears" like Cedric's mother.
23. You paint a tennis ball gold and make your friends reinact the Quidditch match from Book 3 with you.
24. You don't like Harry anymore because he insisted Cedric take the cup with him...
25. ...but if you're a real Hufflepuff you forgive Harry even though it was partially his fault.
26. You feel jealous of Moaning Myrtle for being able to spy on Cedric while he's taking a bath (hee-hee, I do).
27. At Easter you dye all the eggs yellow, both for Hufflepuff's house color and because of the golden eggs.
28: Whenever you see a rat you either run away screaming from it, or you try to stomp on it and yell at it for killing Cedric. ^^;;
29. You frequently talk to Cedric's picture on the cover of GoF...
30. ...and it talks back...
31. You look at the cover of GoF and are convinced that Cedric is looking at _you_
32. And this creeps you out so much you have to either put the book away or turn it over so there's not this dead guy...looking at you... *shudder*
33. You're moving to Britain just so you can get the newest information on the movies, to see when the third one is being cast.
34. And when they do cast someone as Cedric you find out where this guy lives and stalk him (hey, don't put that past me...)
35. You haunt around the Quidditch pitch set, camera in hand (like Colin Creevey), hoping for a glimpse of whoever's playing Cedric