Sadly for most people the idea that something is too hard is a valid excuse to do something. I have no idea why some people choose to skip doing something based upon its difficulty. Most things in this world can be achieved no matter how difficult they are if you set goals for them. Most people would say that losing 50lbs is too hard and therefore they would choose not to do it even if it will better their health and life dramatically.
If your goal was to lose 50lbs don't automatically look at the big picture. Doing something like that will overwhelm you and make you discouraged. Instead set a daily or weekly goal for yourself. Something like eating 2000 calories a day or losing 2lbs a week is a good enough goal that will over time contribute to the bigger picture of losing 50lbs.
Think of it like video game. Each time your character in a video game does something his experience bar moves a little and eventually he levels up. The video game characters small efforts eventually led to a bigger one. Setting small goals will make you achieve your big goal in life.
Once you can go through this process in life once you will feel invincible. You will feel like nothing is too difficult or hard to achieve. Each time you go through this process with any goal it will feel easier and it will eventually become natural to you. So start setting small goals in your life and keep achieving them.