I lost my first 55 pounds at a rate of 1.5 pounds per week. The last 27 pounds I lost at .5 pounds per week. It all adds up. There are benefits to losing slowly. Your skin is more elastic. You get to eat more and can meet more of your nutritional needs. Won't be as hungry. Slow works, too!
While I was losing weight it really helped to weigh only once a week, and even then not paying too much attention to that one event. What I focused on was the lowest weight of each month. That numbered captured my continuing progress much more accurately.
When I think I'm just too tired to exercise, I commit to do 10 minutes of light exercise. If I'm tired after 10 minutes, I'm allowed to quit. But 95%+ percent of the time I feel better after 10 minutes and go on to get a good workout.
I think of my plan for healthy living in terms of a football game. A fumble isn't part of the game plan, but it is part of the game. If I slip, I just shake it off!! It has meant the difference between multiple attempts and success.