Hello, JustWantToBeNormal. Your desire not to harm your daughter's development reflects well on you no matter how you feel.

"I was never like this before, so what happened?" I'm tempted to say, "Depression happened." Something broke inside.

Depression may only be part of what you are experiencing. Anyone - even the depressed - who gains or loses much weight in a relatively short time should see a medical doctor. I hope your situation permits that.