My child’s bedroom looks like something from hoarders

Help! My 8 year old son is such a messy kid, on top of all that he has way too much stuff. His bedroom literally looks like one of those houses on the show hoarders right now. I don’t know where to start or even how to get this done. I have an 8 month old baby to look after so spending a day cleaning isn’t going to happen. Everytime I get his room even the slightest bit clean he gets it super beast again. I don’t know how one kid can make such a huge mess. He gets so upset when I tell him to clean it yet he still tends to make a huge mess. Ugh I’m at the point where I don’t want to set foot in his room. I dread bedtime when I read to him because I can’t even walk in his room. When he was little his room was so clean and bright and sunny and just a nice place for him. Not it’s horrible and I don’t know what to do.