My 3 1/2 month old is now fussing at both bottle and breast. And, I am so stressed out. I started giving her one bottle per day at 4 weeks, in preparation for returning to work. Around the 10th week, she started not liking the bottle. At 10th week, she fussed but would usually finish most of the bottle (3-4 oz). I have now returned to work, the situation has intensified. Sometimes she would cry for 45 minutes and finished only 1-2 oz of milk from the bottle. Recently, she's also started fussing when I try to nurse her. She's now drinking very little per day, and I am worried.