I have to admit that I cut myself for the first time in years today
Are you doing alright? Why did you want to cut yourself?
I feel like I had to do it because I'm not good enough for my friend.
You shouldn't self-harm since it is very damaging to your physical health. If you feel like you are not good enough, that is a sign of depression and you should speak with a therapist or other mental health professional. With help you can learn healthier and more effective strategies for dealing with stress and depression rather than cutting.
I want to cut myself more often.
No no, I really think you need to try and stop this behavior before it gets worse. Cutting yourself will lead to scars that will always remind you. I really do believe it's best to seek a therapist, because you are worthy of a happy life.