The absolute best thing you can do right now is pursue expert professional help, which is what the paed is for. It can be a long process, but figuring stuff out will help you to put your son into a more useful context and allow you to understand where he's coming from better. This is what changes, that and maybe being able to get some help where you guys need it. Also, the sooner you do it the better.
I would suggest looking into the sleep thing, because lack of sleep is a possible contributing factor, and maybe also stuff like diet, too. Sometimes these things all linked together and there's quite a growing body of evidence that gut health is linked to things like autism.