I find it helpful to write down my thoughts in a freestyle manner every night, in the form of a journal. Am I allowed to do this on Chol Hamoed, even though writing is not usually allowed? I know that writing for business or professional needs is not allowed and writing for studying purposes is allowed but I am not sure where journaling falls.

Shalom, Thank you for your question. If you feel that this form of writing is beneficial to your inner wellbeing, then it would be permitted. It would be advisable to write the first line on a slant (not on the printed line of the notebook) as a reminder that it is chol hamoed. Blessings.