I had one of those moments during a scenerio took me like 15+ attemps before i finally got past it. Might i suggest i didnt see you say you tried it but maybe there is a video guide that might help you see something you might be missing. You really shouldnt stress yourself too much to dieing in a dungeon your not used to because personally i find i play worse when i start doing stuff like that, its almost like the more cautious you are the more the game is like challenge accepted.