I have got to the point where I no longer have any sense of perspective.
DS has started behaving in an incredibly manic and silly manner. He says everything in a silly voice, never sits still (I mean NEVER), can't play with us without leaping all over us and ending up hurting us by banging heads and such like. I took him out shopping on our own the other day, normally he loves this and enjoys the one to one attention. On this occasion he started rolling around on the floor of the shop, laughing hysterically as I got crosser and crosser. I ended up picking him up in order to get the shopping done, whereupon he started poking me in the face with his finger and laughing. I just couldn't stop him, the minute I stopped one behavior he started another.
He has suddenly stopped eating again 
, we had made so much progress there. He keeps bursting into tears over problems as well, this is also a new development.
Is this a phase? How should I deal with it?