I think your son can indentify the taste of the milk already. Just like my daughter before 2 years ago. Then I fully breast feed my daughter until she is 2 1/2 years old.
If you need not to go to work you can try breast feed him or you can pump the milk out to feed him via bottle.
and If he is still refuse to drink bottle, then you have ask your maid or your hubby to feed him.
because he can smell you smell.