Four month leap regression?

My daughter is four months and 7 days and been waking up every 2 hours for the past few nights. Her four month appt went well she’s eating well gaining weight and thriving. Well, before this she never slept through the night but she would at least sleep five straight hours at first and then be up once more after that. Well now she’s literally waking up every two hours. Put her down at 7 and she woke up at 9 screaming. Her pediatrician told me not to rock her but to wait to see if she stops crying on her own for a minute or two then go in and don’t pick her up. So I’ve been trying that and the only thing that’s working to make her stop crying and go back to sleep is giving her another bottle (she’s formula fed). Then I asked them if this is the four month sleep

Regression. And the nurse said she didn’t even know what that is which I was shocked about. I think I might switch doctors. They also won’t start her on solids yet even tho I told them she wants to eat like crazy. They said not til 6 months. Does this sound like the regression? And should I still be rocking her to sleep and feeding her every time she wakes up? I feel like she’s eating too much but I don’t know how else to console her. I literally got 3 hours sleep last night. 😩