Well, an obsession in ones life is usually caused by a lack of something somewhere else. In other words, the obsession fills the gap where something else in your life should be. Whether that is a job, a significant relationship, the past relationship with your parents, whatever it is, there is something missing. People with fully rounded existences do not get obsessed, they don't have time and they don't need to.
Rid your life of everything related to this person. Take down the posters, remove the collectables, stop watching the films, listening to the music or whatever you are doing to reinforce the obsession. Next, look at your life, take it all in, what are you lacking? Are you unhappy in your job, your love life, your health, your sexual lifestyle, something needs working on, because you have developed this obsession as a way of fixating on something to avoid something else.
Rid your life of everything related to this person. Take down the posters, remove the collectables, stop watching the films, listening to the music or whatever you are doing to reinforce the obsession. Next, look at your life, take it all in, what are you lacking? Are you unhappy in your job, your love life, your health, your sexual lifestyle, something needs working on, because you have developed this obsession as a way of fixating on something to avoid something else.