Have you tried a sippy cup? That also didn't work for my 2nd son, but is worth a try. Some kids just naturally know what's best and will refuse breastmilk unless it's straight from the source.
What worked for me was to nurse when we dropped him at the caregivers and then they would page me when he got hungry - once he started solids that would hold him over till lunch. Then in the afternoon, I would nurse before driving home and as soon as we got home, just before dinner and then once or twice more before bedtime. Also, for working moms nite time nursing is often a given to make up for the time away during the day and it's really important for maintaining a good milk supply.
My son never had solids at home until he was well over 9 months - that allowed him to still get the necessary breastmilk since he had two servings of solids during the day. Also, my husband and I worked our schedules so I would go in very early and my husband would drop him at daycare around 9pm - I fed him just before I left the house at 5:30 am and then when my husband dropped him off. That would often tide him over till about 11am and then I'd go over and then once in the afternoon. Fortunately, the daycare was 5 minutes from the office. There was, however, a huge benefit because I got to know the caregivers well and I knew that my son was well cared for.