I feel for you. I went through the same thing , 2 weeks before day care. Ugh. Make sure there is no smell on the nipples. Seriously, I couldn't figure out why my baby was all of a sudden rejecting bottles that she used to take no problem. I was trying to figure out "What changed?!?". Then I realized I switched dishwashing detergent. I went to smell the nipples and yep, totally lemony fresh due to Cascade gel packs. The cascade detergent had leached into the silicone nipples! I was using Electrosol before. I tried to handwash them, boil them- nothing got the smell out. So I threw them away, bought new nipples, and then she started taking them again. Now I ONLY handwash all supplies. This might not be your problem, but just a reminder to definitely look at anything that might have changed. I was practically forcing her to take the bottle and thinking if she got hungry enough she would eventually eat. Now I feel awful because she was refusing because of the nipple. . . glad I figured it out though.
Other things that kind of helped us while we were figuring it out
-set baby in boppy pillow or bouncer
- sit behind baby and only put arm in front of baby with bottle so he can't see you
- distract baby with tv (i know. . .but it did work sometimes)
-warm the nipple of the bottle by putting finger over bottle and holding upside down in the warm water for a few seconds
-put the nipples in your bra for a few minutes (before attaching to bottle) to make them smell like you
-check to make sure your milk tastes ok, perhaps you have higher levels of lipase and its effecting some batches of milk (soapy or metallic taste)- my milk only tastes good for the first 2 days. My baby was much more likely to drink if the milk was fresh
-take baby outside to eat
-let baby play with bottle by himself, they are starting to use their hands at this point and sometimes just want to play with it before helping to put it in their mouth
Good luck!!! And remember the folks at the daycare often have NO problem giving your baby a bottle even if you and everyone else you know does. They sometimes have the magic touch and down to business attitude that the babies respond to.