Trying to understand and handle this situation.

Started my self improvement journey and did a boxing class this morning. Was going okay, felt generally disheartened and then i got hit pretty hard in the jaw. From then on i felt like a little boy, wanted to go home and cry. Felt like i was a bout to break down the entire time. Sobbed in the car on my way home for a good 15 minutes before getting myself composed.

Not sure what happened or why and how I should handle it...is this normal?