Coming to an end?

When Kenzie was first born my goal was to breastfeed until she was ready to quit. Then we discovered her milk and soy intolerance and my goal was a year. Then we discovered her intolerance to almonds and my goal stayed at a year. Right before Thanksgiving we had our first encounter with blood in her poo and I had to quit nursing her for two days. I tried my best to keep up with pumping during those two days, but know I could have done better. Since then I've noticed that my supply has dropped some. I used to be able to easily pump 10 oz in the morning and another 5 oz or more in the afternoon. So I got some lactation cookies, drank lots of water, and started taking fenugreek supplements to help increase my supply. She doesn't act like she's hungry or not getting enough to eat, but I just can't pump much anymore. This morning I was only able to pump 5 oz no matter how much I tried. I'm back to being really sore (similar, but not quite as bad, as in the beginning) and starting to dread pumping time. The very minimum I wanted to make it was 6 months, but I don't know if I can keep up. Since the two day break we have gone through the over 100 oz that I had frozen prior to going back to work and now I just feel like I can't keep up. She eats about 15 oz while I'm at work and in order to get that today I had to pump twice yesterday on top of feeding her plus pump this morning while taking my husband to work. I don't know what to do. Would it be horrible to give her one bottle of formula during the day and try to continue with mostly breastfeeding/pumping?