my kid is crazy

I seriously do not know what to do with my child. He has gone from being my sweet baby, to being pure evil. His newest thing is hitting, and not just plain hitting; but looking for an object, picking it up, and smacking someone with it. I have tried everything to stop this, but it is just getting worse. We left a playdate today, because he was hitting. He sits in timeout, I took his favorite trains... then he proceeds to hit the cat. I am losing it with him.

Not only that, but he has decided this week that he does not need to eat... not that that is all that unusual, but this week has been worse than usual. He is not drinking his Pediasure...

I just don't know what to do with him.