I cut myself today on purpose, after years of avoiding it. i am feeling very disappointed in my life. i am on antidepressants. advice?

Medical attention: First, let a doctor examine & treat your injury. Next, if not in psychotherapy, find a therapist & get started. Medications will not solve this part of your problem, but you can with the help of a competent and caring psychologist or other therapist. Dialectical behavioral therapy is a specialized therapy that can help you contain and deal with painful emotions in ways other than self-injury.

Cutting: Cutting releases neurochemicals that make emotional pain less pervasive for a short time. As you know this behavior can become addictive, don't be so hard on yourself, you slipped but get back on track. If you have not already consult with a mental health professional who can help you gain as you have in the past. Best wishes.