My baby feedings.

She is 4months old and she’s been drinking 5oz since 3months but recently just up to now it’s making me frustrated on why she’s not wanting to drink. She drinks every 3hrs and she just now started to drink so slow or hardly any. It could be 3 and the next feeding be at 6 and she still wouldn’t even be done with the bottle at 5:30🤦🏽‍♀️ knowing her next feeding is 6 and she will still be needing 2 or 3oz left meaning she only drank nearly 1 oz or 2and it makes me so mad and sad ! It’s like why, should I try going 4hrs now ? Plz help . ☹️ she’s just on my milk