Stuck on the last mission of the dlc (no spoilers)

Me and a friend were doing what i think is the last boss for the dlc and i died at the end but my buddy finished the boss off. I revived and it spawned me ourside of the fight with no way to get back to it. I thought it bugged out and reset my game and now i have no way to progress further into it. Is there a solution or am i just softlocked?