Why?!

My daughter will be 4 months tomorrow. She’s been sleeping through the night since she was about 2 months old consistently but was starting prior to 2 months. This past week she’s been waking up every 4 hours. Depending on when she goes to bed, it 1am and 5am. I’m exhausted and not sure what’s going on and how I’m suppose to get her to sleep through the night again. She eats a 6/7 oz bottle now, sometimes 5oz but that’s not so often now. When I feed her at 1am, she’s goes straight to sleep, 5am too. She barely sleeps during the day. Maybe about 15/20 mins, 4/5 times a day. Is this all normal. Her 4 month appointment is Monday.