from the looks on that video clip, your lack cardio lost the fight for you. You could barely keep your hands up and even after the fight when they rose that other guy's hand you were huffing like a fat guy who smokes 3 packs of lucky strikes a day.
I would run more and drop a weight class.
No way man, I do the sport as a hobby, not as a career, so its not worth the severe dieting to make 185.
My cardio was fine, see how much Energy you have left when you take a direct liver kick from a 220 lbs guy.
Also dropping a weight class does not necessarily improve cardio, infact it can do the opposite.