Macbook Pro partition not recognized, only Windows bootcamp

Well, macOS still seems to be there with all the necessary partitions. Please don't follow random Internet advice - even on these forums - to do random things in the terminal that you don't understand.

What happens when you hold the Option key down when you boot? Can you choose between macOS and Windows? If you boot into Windows, can you use the Bootcamp utilities to choose macOS as the startup disk?

That doesn't answer the question - which is what does happen when you press the Option/Alt key when booting?

Does it just go straight to Windows?

Does it go to the Boot Manager but there is no macOS option and only Windows?

Does it do something weird and you have to reboot?

And for the second question, if you are in Windows and click the Bootcamp Assistant from the Taskbar, does it give you an option to restart in macOS? If you launch the Assistant's setting app, what appears under teh Startup tab?

OK, well this is more useful! It does appear that both the macOS Recovery side and the Windows side see your partitions. I have a feeling if you could mount and traverse the macOS partition in Recovery Mode all the /System would even be there.

Seems to be a Boot Manager problem...if you are in the Disk Utility in Recovery, you could repair the disk, or run

diskutil repairDisk disk0

Since that might functionally erase disk0s1 (the EFI partition), you should still think about getting a functional bootable installer. I'm not sure you actually have one if you built it on Windows.

Best case, the partition map is repaired. next worst you have to reinstall macOS. Worst case (but maybe the simplest), nuke the whole drive, start from scratch and reinstall macOS and then Bootcamp Windows...