I go back to work within the next week or so and my three month old son is now refusing to take a…

I go back to work within the next week or so and my three month old son is now refusing to take a bottle (he's exclusively fed breastmilk, usually via nursing, but has had no trouble taking a bottle of expressed milk up till now. I have my final job interview tomorrow as a formality (which I was supposed to go to with stuff for putting together an open mic, but my SIL stole my computer), and am starting to get worried about going back to work. It'll be at times where my husband can take care of him and I'm excited, but still don't feel ready.