I feel like the worst mom ever😔

So I have three kids. My daughter is 8 weeks old. She was not sleeping and would take us from 8pm until 1am to get her to sleep. Then she would wake every 2 hours. With my husband working I was the one getting up with her. I suffer from chronic depression and the severe sleep deprivation was causing my depression to get to the point of thinking about hurting myself or worse. I got scared. Desperate for sleep we tried everything. Until one night I laid my daughter on her belly. She went to sleep. No fuss. She actually slept a solid 8 hour stretch. I check on her constantly every two hours cuz I know it’s a major no no for baby’s to be on their belly. But she has been able to lift her head and turn it to the other side. With my son he didn’t sleep on his belly until 3-4 months. Anyways. My daughter has now slept through the night on her belly 4 nights in a row. I feel like a horrible mom for doing this though😥