I used to do it all the time. And now I have these ugly scars on my upper arm that I can never show. So please stop, think of all the positive things in life instead of focusing in the negative ones. You will regret it the day you won't be able to wear certain clothes because you're embarrassed of the scars.
Cutting is a symptom and you're not alone in doing so. It provides a short term relief (in the form of endorphins) to a more deep seated problem. Yes, seek help but know that you are not alone and that you are not going to be seen as some sort of freak.
Use an ice cube on your wrist or pull a rubber band over your wrist instead. These methods are MUCH safer then cutting yourself and release tension. I was recommended these methods by my old councilor and they worked for me when I was depressed.