Break-ups, anger and self-destruction

Yes, you already know that what you are doing is both unhealthy and dangerous to your health and well-being. That's a good starting point.  I don't know what you did 10 years ago that got you to stop, but it sounds like now you need to deal with the root of your pain.  People who do harm to themselves (cutting, burning, self-mutilation, etc.) generally do so to release their emotional pain on a physical level.  Once you effectively deal with your emotional pain, your need to do harm to yourself with stop. The key here, though, is for you to be willing to deal with your emotional pain.  The purpose of any addiction (and cutting/burning yourself is an addictive behavior) is to keep you away from your feelings.  You mention that your life is not going well, and that you recently broke up with your boyfriend.  I am sorry that things are hard for you right now, but the key phrase here is "right now".  We learn about ourselves through life experiences and whatever you are going through now means you have an opportunity to learn, grow and evolve.  Hurting yourself just keeps you locked in a cycle of pain, despair and powerlessness. 

Ok, that said, now you can get down to really dealing with the issues that have triggered an old coping technique. A coping technique that is not effective in helping you to deal with your pain in a real way.  You should absolutely work with a licensed psychotherapist. This therapist should have expertise in dealing with addictive behaviors or at least be someone who has an expertise in helping people to cope with severe traumas in their lives.  Your history of burning yourself tells me that there is some serious pain you have been avoiding for a long time, and you deserve to work with someone who is skilled and willing to help you understand and cope with it.  You might also want to explore doing some hypnotherapy to help you get to the root of your distress so that your habit of burning yourself can be eliminated altogether.  Additionally, neurofeedback can be really helpful in eliminating the internal urge to burn yourself.  It's a great adjunct to talk therapy.  Some additional interventions that people have found to be helpful are Emotional Freedom Technique (EFT), Eye Movement Desensitization & Reprocessing (EMDR).  I would also recommend looking into some meditation, and mindfulness practices to help reduce some of your overall stress, anxiety and depression. 

There are also a number of really great self-help books to guide you along your new path of self-esteem, self-empowerment and self-respect.  My book is one place to start, Being Well Within: From Distressed to De-Stressed  You might also want to read books or listen to audio files by Louise Hay.  Please know that there is a lot of great help available to you if you are willing to pursue it.  You deserve to live fully and feel good about who you are.  Please do not define yourself by a relationship or lack of one... who you are is enough as you are!  That is the start of your healing journey.