We had such a good routine ? She slept for 3 hours during the day, wa…

We had such a good routine ? She slept for 3 hours during the day, waking up every 30 minutes, and could wake up only twice at night for feedings. For the last three days she's been very restless, sleeping for an hour or 40 minutes during the day, being awake for 2-3 hours, and tonight she didn't sleep at all, we couldn't soothe her. She coughs, pulls her feet towards her stomach. We warm the bed before putting her down, she lies on her tummy before feeding, I hold her upright, she poops normally, feeds on demand now, she used to have a schedule. I don't understand what I'm doing