Quitting is not giving up, it's choosing to focus your attention on something more important. Quitting is not losing confidence, it's realizing that there are more valuable ways you can spend your time. Quitting is not making excuses, it's learning to be more productive, efficient and effective instead. Quitting is letting go of things (or people) that are sucking the life out of you so you can do more things that will bring you strength.
Quitting is never an option on the road to success. Find the way forward. If you have a positive mindset and are willing to persevere, there is little that is beyond your reach. The attitude of being ready to work even in the face of challenges and despite odds is what will make all the difference in your life.