The main character ( small ,dark hair , wore a mask if I’m not mistaken)is so in love with this fictional character. He goes to a convention and just to see him and think that the guy was flirting with him. He gets obsessed even more and stalks his social and ends up going to his gym. After the gym he gets a job by his place. Sneaks in place and does unspeakable things and gets caught by cameras

I like freak x freak a lot , red mansion will give you an idea . Can any one suggest more like it ??
Or touch up , it can not be as violent too . I just love obsession or possessive