How strong is your fetish? Do you rule it, or does it rule you? Here is a doctors reply concerning mental illness.
Fetishism may not become an illness unless it starts encroaching upon your normal functioning and relationships. And to call it an addiction, you will have to have the symptoms of addiction. When you start spending too much time looking for opportunities to have your sexual fantasies fulfilled, it may be called an addiction.
Some psychologists believe that sexual fetishism arises out of conditioning of the mind. Today, researches have linked fetishism to emotional problems. A lack of love and affection in childhood may lead to projection of such affection on certain objects such a jacket in your case.
You cannot overcome the urges to act out through your fetish without re-orienting your sexual / orgasmic responses. This process needs time and a lot of hard work and the success rate is limited. If you are able to have a good and satisfying relationship with your partner, you may have to decide if you really want to eliminate the fetishism. Of course, if it is going to create problems in your life and relationships, you may have to consult a behavior therapist experienced in this area.