Weaning to Bottle

I am an advocate for breastfeeding babies. With our DD1 I breastfed her for 22 months and I am planning to do the same with our DD2. But as early as now I am having with my milk production. The supply is somehow slowing down. Our DD2's pedia suggested to supplement my feedings with formula. Right now we started giving her an ounce of formula every three hours. I'll give it to her after I breastfeed her.

Now, our problem is she will fight when we give her the bottle. She'll cry hard and push the bottle away. It's been a week now that we fight every time we give her the bottle. She won't just take it without a fight. I may have to try another nipple for her bottle maybe she'll take it. I really felt guilty that I can't solely breastfeed her but I don't want her to be deprived of additional nutrition as well. I want to do what is best for our DD1.