Looking for a manhwa

What I remember from the plot is that is a guy who can't sleep at night because of some nightmares but then knew a kid (?) But this kid he can sleep for the first time in a while because the kid gets into his dreams and fights the person who's messing with the guy's dreams but in the dream realm he's all grown up protecting the door of the guy's dreams of his moms attacks because in the end it's his own mother who's messing with her child's dreams. Tho she's not his real mom but his stepmom.
I think it's no longer here in mangago because of the thingie with Leznin but I want to know the name of it so I can buy it or something.