Deleted partition in Windows 8.1 (bootcamp) and now macos won't boot
Your best bet at this point is to perform some formal data recovery. 

I've used Data Rescue 4 &amp; 5 with good success.
https://www.prosofteng.com/mac-data-recovery/

I've also used MiniTool's products, on the PC side to recover Mac data.
https://www.minitool.com/data-recovery-software/free-for-mac.html

You can either boot your mac into Target Disk Mode if you can another Mac available. Or, you can create bootable recovery media from either vendor. The third option would be to have professional data recovery done, but that is expensive.

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The obvious lesson here is that a) always have a backup of your important data, especially if you are messing around with partitions. b) Don't make changes to partitions on the Windows side.

Cloud backups are so cheap these days there's really no sense in not having it, just in case.