He has to kill off the mother to escape from spending his life as her son. At the same time, he doesn't dare understand that he has murdered his mother, so this must remain an unconscious act. He only dares to see that she is not longer hovering over him. I'm spelling this out because I want you to see what a wonderful gift your unconscious has given to you. That's why, with most fiction, it's best to throw words on the page as quickly and as unselfconsciously as possible, and then to polish them afterwards.
Most inspired writing is a combination of conscious craft and the unconscious.
You were feeding both of these needs by reading Oscar Wilde. I really am very taken with this piece of work. I wish I could suggest some place where it could be published, but that's not so easy, since most children's publishers would be scared off by the ending. That's another reason why I wanted to spell out what I strongly feel to be the meaning of this piece - so no one will ever persuade you to change the ending. Also, if you can explain it, you have a better chance of getting it published.