Re: quit working for kids
16 month is a time when the child is more aware of his/her surroundings. May be your child will not, but most of the kids this age have separation anxiety, your child will understand when you drop him off, most probably will cry more as well because he knows and can understand that you are leaving him. IMO, I think it is more difficult to drop off a 16 or 18 month old then a 3 month old.
My intention is not to discourage you from taking up the job, as I stated earlier I have been a working mother myself.
What kind of worked for me was to find a home based baby sitter. My child was more comfortable because it was a home and she was the only child in the beginning so she got undivided attention from the baby sitter and also lot of attention from the entire baby sitter family.