Both unilateral and bilateral contracts are enforceable in court. For example, a unilateral contract is enforceable when someone chooses to begin fulfilling the act demanded by the promisor. A bilateral contract is enforceable from the get-go; both parties are bound the promise.
Yes, scratching is a form of self harm. Try to tackle this problem while you can because it has the potential to get worse. I started out scratching and now I burn myself with a lighter and cut myself. It's a self-destructive way to deal with overwhelming mental/emotional pain.
What Is Self-Sabotage? Behavior is said to be self-sabotaging when it creates problems and interferes with long-standing goals. The most common self-sabotaging behaviors are procrastination, self-medication with drugs or alcohol, comfort eating, and forms of self-injury such as cutting.