textured food

my baby is 8m old and only eating cereal once every 2-3 days. recently he’s been rejecting milk and don’t want any cereal. am I lagging? some of my friend’s baby can already eat textured food. my baby doesn’t know how to bite at all even with 4 teeth. he will just bite a big piece and try to swallow. am really stress. he is losing a lot weight :(