S.W.
I went through this when I needed to start taking my daughter to daycare at 3 mos. She would not drink from a bottle. She ended up going six hours a day at daycare for four weeks without drinking! She was perfectly happy to be there, until they put a bottle in her mouth then she screamed. On Monday of week 5, she drank (?)
Here are some things we tried:
heat the bottle up to body temperature
have someone else feed him if possible
use a bottle with a nipple that most resembles yours