A.H.
I've introduced baby food at 6 months with all my kids so I am not an expert but stage 2 at 6 months seems early...I agree another previous response in cutting back on the food...I can only imagine he's too full to relax and sleep. And have him lay down for a nap even if he doesn't go to sleep just start giving him that pattern and perhaps that will help him...babies are really grouchy when they are overly tired!