The comment that hurts most may still need to be separated into its useful and careless parts.

A painful comment is rarely all one thing. Somebody clumsy or angry can still have seen something real, and the accurate part arrives welded to the careless part, so rejecting all of it is the natural response. Keeping all of it is no better, since much of what was said belonged to their mood rather than your work. Separating the two is slow, and it usually goes better later than now.

Set the remark aside for a few days, then write down only the part you would accept from someone kind. Let the rest go without needing to argue with it.