MacOS and windows not booting anymore after deleting EFI partition

Hello together,

I recently reinstalled my bootcamp-partition (was 750gb macOS / 250gb Windows first) using the bootcamp software on macos. everything worked out great, till I noticed macOS only having 500gb storage and windows using the wanted 250gb. So the last 250gb were like „gone“. In Windows i saw unused space on the SSD, but I couldn‘t resize the macOS partition because I would have to move it first. 

I also saw a OSXRESERVED partition and some 16mb partition (that was probably the EFI), so I deleted both, booted into Gparted via a live USB and moved the bootcamp partition to the right.

Restarting to macOS, i saw the free space and resized my macOS partition to 750GB, but from then macOS wasn‘t shown in the boot-selector and windows doesn‘t boot (only a blackscreen).

How can I fix this? Do I have to reinstall everything? Can I recreate the EFI-Partition?

My specs:

• Crucial P2 1TB SSD
• Macbook Pro 2015 15“
• macOS monterey / Windows 10 (everything latest)

Thanks for your answers.