growth spurt or sleep regression

babydylan2015

My little one is almost 16 weeks old. Previously sleeping 7 to 10 hours. The last 5 days He wakes at 5 hours screaming and feeding is only way to calm him. Then he will go another 5 and so on. He has recently started eating more with a new formula I think it tastes better to him. I'm talking from 4 oz of other stuff to 6 or 7 of new formula. At night we feed him 5 if he wakes up. He weighed 13 pounds 6 ounces in Friday. I brought him yesterday and he is 13 pounds 14 ounces. So ladies growth spurt or sleep regression. I might add he doesn't really nap except 1 3 hour nap during the day now. Words of advice, encouragement etc are appreciated!