Not my face specifically, but as a teenager my whole body sometimes suddenly had a different sense of size.
For my body as a whole, I also don't have an inner sense of a permanent body morphology that is "mine", so with one exception[0] I can't even imagine what it's like to be body-dysmorphic — even if we lived in a world of magic gender/species transformations that might happen with no ill effect, if I woke up and found that had happened, the only concern is if society can cope with it, not one of my own inner psyche.
The one exception is forked tongue. That is a sticky morphology to imagine, and one I don't like at all. It's also something a friend got done surgically. Good for them, they seem to be enjoying it, it makes me go "aaaa".
[0] I assume there are limits beyond my imagination, but my imagination does at least include tails, wings, gender flipping, and I've listened to the We Are Legion (We Are Bob) series.