I'm sorry to hear you are struggling so much at the moment. You can get through this! It is possible to overcome. It takes time and patience and being gentle on yourself though

We all struggle and slip up at times.
I know those cravings - I know how hard they can be but they do pass and in time they do get easier to manage. In time you can find a release that doesn't involve harming yourself. There are a lot of different suggestions of things that have helped people in
this thread.
Can I ask why you stopped taking the Naltrexone? Is your doctor aware? They might be a good place to start if you haven't spoken to them. Also, do you have a therapist? While medications can be extremely helpful it can also often help to have someone to talk to and to work on other coping strategies so that maybe you can manage without the meds but also manage the cravings as well.
There is a world for you where your only outlet doesn't need to be meds or cutting. I know it sounds crazy at the moment but it is possible to do.