YouTube says it will switch off comments on almost all videos featuring under-18s, in an attempt to "better protect children and families". YouTube didn't cripple your channel, they just disabled your commenting feature which is something that you actually control.
With a few simple steps, you can turn them all back on but there are few things you NEED to know first. I'll walk you through every step so that you can get your YouTube channel and all of your comments back up. read here YouTube channel