A tool can group comments quickly, but a useful summary should let you trace a theme back to the actual feedback.
Give each comment a reference number and remove details you do not need to share. Ask the assistant for topic groups and a list of reference numbers per group. Keep multi-topic comments linked to each relevant theme and preserve an uncategorised group for difficult examples.
Read a few examples from every group before reporting counts. Check for near-duplicate responses and separate the number of comments from the number of customers when you have both. Save the original list and the grouping rules together.