You need to make sure your Grub is on the partition you think it is since you deleted and recreated a partition. Use the Live CD of Mint, open a terminal and get to a grub prompt by typing: sudo grub
Then type find /boot/vmlinuz and check the results.
I'd suggest creating a mount point other than the /mnt directory for Mint. As root, sudo mkdir /mnt/mint, then mount it as root:
sudo mount -t ext4 /dev/sda5 /mnt/mint
See if you can browse your Mint files. Particular attention to the /boot/grub/grub.cfg file which should contain your menu. See if it pointing to the correct partition.
I have not used Grub2 so can only point you to this tutorial for info: