You could try thinking about different things, like your goals or plans for the future. And give yourself some time; eventually, your mind might naturally move on from the fictional character.
It could be because the character has qualities or a story that resonates with you on a deep level. Maybe they represent something you aspire to or remind you of a part of yourself.
You can't stop thinking about a fictional character for various reasons. Maybe their struggles or achievements resonated with you on a deep level. Or it could be that their appearance, skills, or relationships captured your imagination and left a lasting impression.
Try to diversify your interests and engage in more real-world activities. That way, you won't be so fixated on the fictional character. Also, think about the flaws of the character to break the idealized image in your mind.
Try to focus on their flaws and negative traits. Maybe that'll make you less attached.
Try to focus on real-life relationships and experiences. That might shift your attention away from the fictional one.
Diversify your interests. Engage in new hobbies or activities that take your mind off the fictional character. Also, think about the flaws or unrealistic aspects of having a crush on someone who isn't real.
One way to stop is to remind yourself that the character is fictional and not real. Also, limit your exposure to content related to them. For example, don't constantly re-read or re-watch the material featuring the character. Instead, explore new things and expand your interests.
Try to focus on real-life activities and hobbies. It can help shift your attention away from the fictional world.
Try to focus on real-life relationships and activities. Meeting new people and getting involved in hobbies can shift your attention away from fictional characters.
Diversify your interests. Engage in different hobbies or activities that don't involve the fictional world. This can help shift your focus away from the character.