I need help and answers ...

So my son who has downs just recently had heart surgery isn't sitting up crawling or walking he is 14 months old .. he cries in his Walker he just started to hit things but doesn't have interest in toys .. he claps and plays with his feet he doesn't like to be on his stomach for tummy time he will roll though..he dont hold his own bottle or grab at his food or spoon he holds his head back like looking at the ceiling he is really like a newborn to me still