6 week growth spurt? Is it real?

My baby was the happiest last week - so chill, woke up calmly. He turns 6 weeks tomorrow and the last two days…Wow. Feeding constantly - every 3-4 hours? Yea right. It’s like every hour and a little here, a little there. We are wasting so much BM and formula because we can’t time and feed him as we normally do. If he’s not sleeping, he’s fussing or crying the last two days. He IS sleeping like a champ though.

Is this the 6 week growth spurt?? Is that really a thing? I hope it is because I can’t take this much longer. He just seems so unhappy and I can’t figure out what to do