Yeah It is realistic to lose 60 pound.... But you wont have "lean muscle" built on by May.... Lose the weight first through calorie counting and cardio with some high rep weight training.... and then once you lose the amount of weight you want, start lowering the reps and raising the weight that you're lifting...
Cut out everything that is WHITE(Bread, etc..), No sugars, small percentage of fats...
Only eat carbs around the time you are working out(within 2 hours)... Post work out(Sweat potatoes, brown rice, etc.), or Pre workout(Oatmeal)...
It should take you 9 months to a year imo to cut the weight and build lean muscle.... Like someone else said, slow and steady wins the race...