When you feel that you are working very hard, you should stop and see if you have made a mistake in what you are doing...
The concept of "God rewards hard work" has a far greater meaning for universal domestication than reason.
If you are on the right path, you will either enjoy the process immersively and not feel that you are working hard at all, or enjoy the push of potential energy and be carried away.
If you are struggling with "hard work" and "self-discipline" every day, most of your energy is actually consumed in internal struggles.