We really like to see your system but I think, for you, it is best you reinstall. It's easiest for you.
But if you want, boot up a liveOS and from it, provide
contents of manjaro fstab
sudo parted -l
contents of manjaro boot
Your /boot/efi shows only 4 KB and that should be about 100 KB. Even though my link don't need a /boot/efi to boot to, I think you have more issues that you and us here have figured out.
I prefer you not to reinstall and we can see what went wrong with your system but that will be selfish of us. It will be easier for you to reinstall.