How have you determined this? It makes a difference. I found this page on System76 website... the people who make Pop_OS. On that page they describe how to repair both the systemd-boot and GRUB bootloader and how to determine which you are using. I'm not sure your bootloader is "broken" since it boots Pop_OS, but maybe so.im installed it in legacy mode instead of uefi.
sudo update-grub... let us know what the error says. This should be easier than following the complicated steps on System76's website.
You really should not have needed to create a boot partition... there already was one (from Windows) that should have been used by Pop_OS in a UEFI installation. They should share that partition. If your Windows was a UEFI install (probably) and you did a Legacy install for Pop_OS, this can often cause problems. This may be where you went wrong.when i installed linux into the partitions i made a boot partition instead of a linux-swap partition. is that what i did wrong?