Link to original: http://sphynxcatvp.nocturna.org/articles/sc-control.html
How well you deal with setbacks and possible flareups will dictate how well this will work for you. Do not be afraid of yourself. You are still the same person you were before, vampirism just adds a new level of things to deal with. The "what" is not as important as "how you deal with it". Whether you call yourself a vampire or something completely different is up to you - it's only a word, after all. If it makes you feel better, don't use "the v-word" at all!
Learn what triggers "vamping out" (occasionally referred to as "twoofing") and avoid the events or things if possible, or limit your exposure to it as much as possible if you can't completely avoid it. A trigger is anything that can start your mind thinking about blooddrinking and ways to get blood. Events that can trigger this problem include watching an intense vampire movie with lots of bloodshed, reading a book/comic with simaler themes, etc.
If you "vamp out" or "twoof", don't panic. - redirect it or find something that you can use to distract you from it. Things that will physically wear you out are recommended, such as self-defense classes, playing the "Dance Dance Revolution" game, perhaps even contact sports such as football or first-person-shooter video games such as Half-Life or Doom 3.
Another distraction method is to use pain - and I don't mean "cutting" either. What has worked for some is to use an elastic band, or rubber band, on the wrist (obviously, a thick one, and large enough so that it doesn't cut off your circulation if you're wearing it all day) and when you feel the Thirst building up, snap the band - pull it away from your arm an inch or so, then release - and use the resulting pain to distract you.
It might help if you go somewhere really noisy - or really deserted (so you don't panic neighbors) - and do some really loud screaming to get the frustration out. Examples of good noisy areas would be clubs with really loud music. If you live in a city, a club might be an easier option than trying to find a deserted area.
And don't forget the various substitution methods - try several, what works for one person doesn't always work for another.
It *is* possible, just not fun. In order for this to work, you need a mindset that can adapt to your needs, so that you're only fighting one thing at at time. "Freaking out" about craving blood won't help you try to suppress it because you're not only fighting the Thirst, but also your fear of it at the same time. It's more effective if you're only fighting one battle at a time instead of two.
Suppression is basically ignoring the Thirst, pretending it's not there, or refusing to acknowledge it. This takes a lot more willpower than simply redirecting it, since you're not giving it *any* outlet. Depending on your situation (home, school, etc.) this may be the only option if the various substitution methods don't appear to work for you.
Regardless of which method you choose - control or suppression - it will be MUCH easier if you keep yourself healthy. Eliminate as much junk food - sodas, "McFood", chips, etc. - as you can from your diet. The same with artificial sweeteners - they're just more toxins, which create more work for your body to try and process. Add more veggies and fruits to your diet, ensure that you're eating good quality meats when you do eat meats. Take vitamins - you may not believe they'll do any good, but a good quality multivitamin in capsule format certainly won't do any harm.
(For more information on this, see my article on keeping yourself healthy.)
In short, provide for your body's basic physical needs and nutritional requirements. Listen to what your body is telling you, too. If you're hungry, get REAL food, not fast food and junk food. Your body will thank you for it, and the blood cravings will be MUCH easier to deal with.