Well basically it's like this. The heavier you are the more calories you are going to burn doing your day to day routine. So when you're at a heavier weight and you are exercising and eating right you're going to be calorie deficient fairly easily. As you lose weight, the calories that your body burns doing it's normal activities decreases. So, as you lose weight it will be harder and harder to get a calorie deficient day. See what I mean? Basically the more weight you lose the less calories you burn doing your daily routine. So that's why the 'last 5 pounds' are so difficult to burn off.
However, if you keep exercising and keep eating healthy you will continue to lose weight, just at a slower pace. As you get closer and closer to your goal it will be harder and harder for you to continue to lose weight.
As you are losing weight you should be adjusting your diet accordingly, while maintaining at least 1200+ calories. This will help in keeping your weight loss a little more constant, but it won't stop it from slowing down.
Also, your body gets used to your workouts. For example, your first day at the gym, you run for 10 minutes and you get your heart rate really high because you haven't exercised for so long, then you will burn a lot of calories. If you do this for a month, by the end of the month you'll be in much better shape, thus you won't be getting your heart rate high enough to burn as many calories as you were at the beginning of your exercises. So adjusting to how fit your body is important, go by your heart rate, it's the best indicator of how hard you have been working.
The fact that your weight loss is slowing down is not a bad thing though! Don't think because your 10pounds/month has turned into 5pounds/month you are doing something wrong. I know you want to see the numbers on the scale go down but this is simply your body adjusting to a healthier lifestyle! If you think about it, this is a very healthy occurrence and you should be happy that you have made it this far! If you make this weight loss into a full on lifestyle, your body will eventually get to it's healthy weight. You'll look great, feel great, and have loads of energy!
In conclusion, the latter part of a weight loss is not 'harder' than the first part. It just simply takes longer. Don't get discouraged, your body is transitioning into a healthy lifestyle and you should be very proud of that. If you want to keep your weight loss going, you should be adjusting your diet. As well, you should constantly be increasing your exercises, whether it be time or just tempo you need to adjust to the strength your body is gaining to maintain the number of calories you were burning at the beginning of your weight loss journey.
Congratulations on your accomplishment so far you've done an excellent job. If you keep up your determination, you will continue to lose weight. Hope this helped you!
