Data not backed up, System not booting, Getting Error: -69845 after trying to fix bad Partition Type
After looking through more threads I found my own problem. The type for my partition was supposed to be APFS so by using the previous solution with the correct type as in 

diskutil umountDisk disk0
gpt remove -i 2 disk0
gpt add -i 2 -b 409640 -s 372637568 -t 7C3457EF-0000-11AA-AA11-00306543ECAC disk0


Now I did come across a problem at first because diskutil verifyVolume disk0s2 gave me Unrecognized file system (-69846) 
I did not mind it and tried to reboot after NVRAM reset and I was able to boot back to my Macbook as I did before with no loss in data. After that I used the command :

diskutil apfs resizeContainer disk0s2 0


in order to be able to use the memory from erasing my linux partition. Hope this helps someone.