You can start expecting results after about 3 months at least. Give your body some time. You did not get out of shape instantly so do not expect to get into shape instantly. 

Instead of exercising more you must exercise more intensely. The more intense your workouts the briefer they will be. Spending 3 hours in the gym only signifies lack of intensity. 

So what! It’s never too late to start. If you have never exercised, you need to start your exercise program by simple exercises and not workout too hard initially no matter what your goal. 

Muscle in the body. The more muscle we carry, the faster our metabolism and hence lesser the fat. Also choose exercise form such as weight training.