One side effect of hypnotherapy is dizziness.
This could be a small or a big matter.
Being giddy is rather a frequent occurrence that happen to many people. It could be a result of hungry, medicinal effect, playing games that spin the head, eyes rotate in big movements etc.
Just be sure that if diziness occur, do not aggravate it with caffeine or alcohol. Do not drive or walk about immediately. Sit and rest for a while before proceed with the walking or driving.