I definitely agree with Blue_Bird and they have some great advice. You have the right to feel how you do, no matter what that is. Everyone has different backgrounds, experiences and emotional reactions and all should be acknowledged and respected.

And it can can help sometimes to look at self harm as a form of addiction. You may not start with the intention of continuing but it can take over. It becomes a coping mechanism when other ways of coping haven't worked, or no longer work. By self harming you release adrenaline and endorphins, which are basically the bodies 'happy drugs' and can help in times of stress. Unfortunately like most addictions in time though people find they need more and more to be able to cope and the self harm can get worse to achieve that.

If you are seeing a therapist that can be a great support. Also, with self-harm one of the best tools you have to manage is through distraction and finding other coping mechanisms. That could be through writing, drawing, listening to music, singing, running etc. Anything that you find enjoyable and relaxing. Exercise can be extremely helpful as it also releases endorphins into your system.

You may also want to look at the threads stickied in this forum as they give a lot of good information on self harm and distraction techniques. I will link them here as well:
Reasons not to
Things to do instead of hurting yourself
Self injury resources

And also, please feel free to ask questions and seek support here. There are some amazing people who I am sure will do all they can to help