If the Spells Don't Work
Lets say you have performed one of the rituals or spells here or elsewhere to help you defeat self-injury and you still feel the urge to cut, you still feel depressed, things don't seem any better.
Don't worry, and don't berate yourself for having done something wrong. What you have done in performing one of these spells/rituals is to start a process. There are no quick solutions to many-layered problems such as self-injury, and it will probably take some time. But you have made a start, and are making a conscious effort using magic, will and ritual to overcome self-injury. You have started on the road to recovery and you have the power to see to the end of that road. Don't give up - you will make it.
Remember, too, that spells and rituals are not an alternative to medical help. If you are on prescribed medication for mental illness, or seeing a therapist to help you work through your self-injury, then do not stop. And do not trust any group of any faith who tells you to avoid medical help. The divine works through those methods too.
You may also find that the spells and rituals work better if you customise them to you - write your own words, dedicate them to Gods that you work best with, that sort of thing.
Keep fighting: it is hard, but you have power and strength to defeat self-injury. It may take time, but it will arrive.