Hello there, you did the right thing in reaching out.
There are as many different accounts of bullying as there are bullies that walk the earth, but there is one universal constant when it comes to bullying; bullies target people they consider weak, for whatever reason best suits them.
If you want to stop the bullying, you're going to have to discern what it is about you that bullies target and use against you, then have a good, long talk with yourself about that trait that makes you a target to bullies, to determine what you're going to do.
One thing is certain, something has to change, because if you just keep trudging along, you'll find that bullies will go an abnormally long distance out of their own way to bully someone.
You need to build a support group and stop weathering the abuse alone. No single piece of advice will stop all bullying, but bullies tend to leave alone those targets who move in groups. Bullies mostly leave their targets alone when higher authority figures are around, so you can make a point of being close to an authority figure as often as possible, but all of this is very passive.
If you want to solve your bullying problem, you're going to have to do something very deliberate about it. Maneuver your bully into getting caught, catch them around an unobserved corner and sort it out face-to-face when they don't have a crowd to perform for, since many bullies only bully because they like being the center of attention, or you can even make the effort to turn a bully into a friend. You have many options, but in the end it is up to you to take charge of your situation and figure out your solution.
(WARNING: If you choose to confront your bullying problem with violence, know that many bullies go on to develop severe anger problems, and when a bully's target "dares" to stand up to them, it can provoke them into a more aggressive response. There is never any telling whether a good sock to the mouth will fix a bully; sometimes it does, sometimes it does not. Only resort to violence if it becomes your true last resort.)
But there is one thing that does not change in all of this, and I consider this my Prime Directive: It Is Never Okay To Be A Victim Don't tolerate it, don't allow it into your life, and for certain, don't fall into the mindset of a self-victimizationer (pardon the made-up word); that is a person who deliberately becomes or finds themselves in a situation where they are a victim because it gets them attention.(Also known as Munchhausen's Syndrome)
When it comes to cutting, that is a simple explanation. Anytime your body exerts itself, it hurts at first and then releases feel-good chemicals to numb any pain and soothe the healing process. It is that feeling, that process, and that minor temporary sense of relief that cutters become addicted to. You don't need to cut, you need to get away from your antagonizers and do things that make you feel better about yourself. You need relief from your stress.
Please keep in contact and let us know how things are going in your life. If you feel like you may hurt yourself or someone else, contact the National Suicide Prevention Lifeline at 1-800-273-8255. Their lines are open 24 hours a day.
Never forget that you matter, and you are not alone.