Feeding Dilemma

At first Abigail was taking the Alimentum, but now she is refusing anything but breast milk. Even when I know she is hungry, she will not eat until I nurse her. So, not sure what to do. My supply is way down. I've found an alternative to dairy milk ( Almond milk, which I often drink) and to butter ( Earth Balance buttery spread) but have no idea what to do about cheese. I couldn't find any vegan cheese at the store. It's in so many of my recipes, as is all of the cream soups, etc. And the protein bars that I live on have dairy as well and it took me months to find a protein bar without a lot of sugar that was edible. To me, this is one of the most difficult things about newborns: figuring out what to feed them. I pumped and bottle fed Olivia for 6 months because she never took to nursing. I also had to bottle feed to add in her medication. Plus, we had her on Neosure for weight gain. She projectile vomited almost every bottle ( that was fun ) and we finally ended up having her on Enfamil AR which she kept down a lot better. But trying to figure out what my babies would do best on is such a struggle for me. And this no dairy thing is harder than it sounds, especially when you have a family to feed. I find it such a coincidence that her diarrhea problems started right after I got on my antibiotic. She went from going every 3-4 days to 10-15 times per day. So I'm not completely convinced that it is a milk protein allergy. But I'm now off my antibiotic and it hasn't improved, so maybe it is. Just wish I knew what to do.