I admire your courage in coming to PsychCentral to deal with this question and you searching for information. While online quizzes and tests shouldn’t be used to diagnose, they are a great way to see if you meet the criteria for a particular disorder. From your description and results of these tests, it is safest to proceed “as if” this is what is going on (read below for the “rule out” diagnosis.)
As identified in this linked article: the name of what you are discussing is excoriation disorder (but has also been called chronic skin-picking or dermatillomania), which is a disorder where a person picks at their face, arms, and hands, etc, and from what you describe—most likely your collarbone qualifies.
The central feature is recurrent picking at one’s own skin. But it isn’t picking alone that makes it excoriation. As the article will explain, skin rubbing, squeezing, lancing, and biting are also common. Most individuals pick with their fingernails, although many use tweezers, pins, or other objects.
Technically, this condition (as this test will identify) is often classified as an obsessive-compulsive disorder. There is a lot of very good therapy for this, and I would highly recommend seeing a cognitive-behavioral counselor/psychologist for this. Therapists trained in CBT have a particular way of approaching these conditions that tend to work. Ask around to find someone trained — or use our Find Help button at the top of the page to find someone that may be near you in your country.
The “rule out” possibility may come from the medical condition of entomophobia, the fear of insects, and the scratching you are doing because of it. This is why a trip to the psychologist might be most important thing you can do as he or she can help with the treatment in either case.
While I understand going to your physician may be difficult, you may want to go just to make sure there are no infections.
Wishing you patience and peace,
Proof Positive Blog @ PsychCentral