Do not be afraid to take a couple of days off occasionally. Just as muscle needs time to heal, the mind needs time to refresh itself. After taking a short time off, you may return to class refreshed and full of enthusiasm. Taekwondo should be fun, not drudgery. Try not to take more than two consecutive days off at a time.
It does not matter how slowly you go so long as you do not stop. -Confucius
Without perseverance, you will not learn that technique that is giving you a problem, learn that new pattern, or learn how to improve your sparring. Without perseverance, you will probably not even come to class! Statistics show that fewer than five percent of students who join as a white belt actually make it to black belt. Why? it is because they do not have the perseverance to give themselves a chance to achieve black belt. There are many demands on your time and the study of Taekwondo will compete with these demands. If you enjoy Taekwondo, then commit to it and persevere. If you try, and you travail, you will triumph!