No one has the right to make you feel uncomfortable or fearful whether it is in cyber space or face to face. The problem is not you, it is your tormentor. People who do not feel good about themselves tend to try and visit their unhappiness on others. The person who is targeted tends to feel isolated because frequently they do get a lot of support from their peers. It is not that their peers agree with the bullying or are indifferent to what is happening. They are afraid if they say something they will become targets themselves.
In situations like this it is best to have an adult intervene. This is not being a “snitch,” it simply is a way of dealing with an issue in a mature responsible manner. If this is happening in school then the professionals there should be used to dealing with this type of behavior and be able to handle it in a discrete way.
Talk to your parents and let them know what you have been going through. It is better they find out from you before you wind up "lashing out" and someone else will have to tell them. Come up with a plan that you are comfortable with and let your parents try and resolve it through the school or talking with the other parents. You are entitled to live and go to school in a safe environment.
For a lot of great information on this topic check out TeenHealthFX’s Where Can I Go for Help with Cyber bullying Issues?