Formula or DF diet

Hi everyone. My LO is 3 weeks old and overall seems happy (minus witching hour) and is gaining weight. She started having super frothy and mucousy diapers, followed by a few with blood. I took her to the pediatrician and they suspect CMPI.

I’m so torn if I should continue to EBF and cut dairy, or just switch to formula. I just want her to feel better faster. I also feel like breastfeeding is depleting me. I have lost so much weight and feel like I can’t eat enough, so cutting diary sounds hard. Formula downside is the expense. Would love to hear any experiences yall have