I found that stage awful, tbh. Also silent reflux and a bad sleeper.
Everyone told me the reflux would improve at 12 weeks cos the muscle would strengthen and I was so skeptical, but they were right.
She did then hit the 4 month sleep regression, which was hell.
My memory is a bit off (it was a whole year ago
) but I found it got easier in general as she became more alert and smiley.
She also got into a decent routine at some point which I found easier as I like a routine, can't really remember when that was - probably not far off 9 weeks though.
Six months when she could sort of sit, we began solids etc, that helped a lot.
We moved her to her own room at 7 months and she suddenly started sleeping through most days which was a revelation.
And from there, it continued to get easier as her routine evolved, she developed etc.
But really for me the biggest change was going back to work at 9 months. 