Hello! I am sure that you can get in a good shape as you were before. You need to combine diet and exercise that is a powerful combination. You should eat a high protein diet in order to lose fat and not muscles mass. You should eat proteins such as: egg, fish, milk, yogurt, cottage cheese, cheese, chicken and try to cut as much as possible carbohydrates such as: bread, rice, spaghetti, cookies, desserts. Try to cut totally saturated fats such as : butter. Try to consume fats from fish and nuts. And exercise, weight training and cardio. So you your metabolism rate will rise the more muscles you will build more calories you will burn. Best regards