Stressful weekend

My 2.5 yr old flunked sink or swim potty training this weekend. My 9w old March baby has blood in her poop again after being diagnosed with a cow's milk allergy at 6 weeks, and I have not had any since then. And just tonight my dog bit my toddler in the face, unprovoked, after never showing a lick of aggression. (And I was a vet tech so I read her well and am extremely cautious with their interactions) Luckily it didn't break skin but it could have been devastating. I can't stop crying. All I want to do is eat junk food and I can't eat anything because of my restricted diet. I can't stop crying. Of course there is no doubt in my mind that I have to get rid of my dog, but that doesn't make it easier. I love my dog so much and it's just so upsetting to be in this position. She also has seizures so between the bite history and health issues I don't know if i'll be able to find a rescue that will take her. Additionally, i'm trying not to think about my maternity leave being over in 3 weeks. It was a really tough one.