Playing melee classes in dungeons always drives me crazy, mobs seem to be a lot harder on anything close to them over ranged classes. It might just take you a lot more practice to get down boss patterns and the such. Don't be afraid to tell your group it is your first time in there either. Most people are really understanding, and will give you tips on the fights, so you don't go splat to mechanics

http://na.finalfantasyxiv.com/lodest.../blog/2497062/ <-- monk rotation talk