Dis-comfort
The prefix added to the word "approve" to make it its opposite is "dis-", resulting in the word "disapprove."
The prefix for comfort is "com-".
UNfreeze
un as in unbolt.
Im- is the correct prefix. This would make the word immature.
Hypo is the opposite of the prefix hyper.
The prefix "in" could be used to make the opposite word insufficient.
The root word of discomfort is "comfort."
discomfort
uncomfortable
I'm preaty sure you would add dis- to make it discomfort
The opposite prefix of the prefix "meta-" is "pre-".