I feel like a failure at breast feeding.

Me
I have never been able to make enough breast milk and have camped out several times with my daughter, pumped, reglan, mothers milk tea, lactation cookies, etc. Things started going great she started to breast feed more I got up to 2oz every 2hrs..now my daughter has had horrible diarrhea for 12 days. She was diagnosed with a cow's milk and soy allergy today. I was advised to pump and dump for 6 weeks until all soy and dairy is out of my system or to quit..I barely make enough as it is and now this. Its a lot to pump and dump and change my whole diet with no dairy or soy what so ever. I feel like a failure and it just makes me so sad I won't have that connection with her anymore. I had manic depression before pregnancy and I just want to ball my eyes out non-stop. I feel so wounded from this. I just want my little girl happy and thriving and healthy.