In my normal playthrough, I finished the main questline and started a few missions in Oasis in the Pirate's Booty DLC. Today, when I clicked on the Continue button, no matter what I do it starts from the very beginning of the game with my leveled character. Is there a way to get back to where I left off?
When you finish the main game for the first time, the next time you load that same character, you will be in True Vault Hunter mode, also called "Playthrough 2". In that mode, you will be starting the whole game from scratch, with tougher enemies, and more levels to gain.
If you want to go back to Normal Mode, and continue the playthrough you were on, go to the main menu, hit Select Character, and choose the same character again; a prompt will ask which mode you wish to play.