Usually when you think about getting or staying fit, you think about it from an outside perspective. Your mind automatically goes to an image in your head of what you want to change and how you want to look. Those images can even be of another person that you compare yourself to and wish to be like. You want to look good first, and feel food second. Sometimes you don't even think about wanting to feel good because you have been in your current physical condition for so long that you don't even realize that you could feel better and have more energy and strength.
When you don't use your muscles, they start to break down and turn to mush. They become more and more useless as time goes on. Years of neglect and poor diet result in muscle loss. When you look in the mirror and see that you are not as cut as you once were, it's vainly frustrating. But think about what you CAN'T see. Think about your heart, for example. If you're looking in the mirror and noticing a huge lack of muscle, or experience being a lot more weak than you used to be, or get winded just walking to the mailbox, what do you think is going on with one of the most important muscles of all?
I think it's awesome to want to look good. Everyone should feel good about themselves. And if you work hard at being healthy, it's only fair that we are rewarded for our hard work with fit bodies that we aren't ashamed of. But when this is your primary focus, you are missing the whole point. When you get it in your mind that you want to be a certain size/weight/build, and you start working toward it but aren't happy with how fast you're changing on the outside, you're messing up. Think about a deep infected cut. It looks awful and you want it gone now. You can cover it with a bandaid, but until you do something to heal it from the inside out, it's not going to go away. But with proper care, despite how it may look on the outside, it is healing. It takes time and you may not be able to see it for awhile, but it is healing.
When you set out to change your ways to permanent healthy living, the inside is where you need to start. If you step on the scales once a week and feel as though the efforts you are making aren't doing a thing, get rid of the scales and keep working. Eventually you are going to notice that your pants are getting saggy, people may begin to comment about what they see, and that number on the scales will finally start going down. Scales can be your worst enemy. You can be within a healthy weight for your size, but be fat. Just as you can be above a healthy weight for your size, but be extremely fit. There's more to fitness than that number on the scales and what size pants you're wearing.
If you want to see REAL changes in your health and fitness level, start by working on the inside. Get your cardio and strength training in. Eat healthy foods. The rest will come in time. Just keep your focus on what really matters.