I'm looking for a word or phrase to describe someone who doesn't handle emotions well. Not someone who has no emotions or is bad at relating to others, but someone who does not cope well with powerful emotions (mostly negative, but could be positive as well, like if they're afraid of relationships and find themselves falling in love). Something that might describe someone who immediately falls to unhealthy coping mechanisms to deal with or all-out avoid situations they don't like.
Ideally, this might also refer to someone who ignores/buries their emotions until they "explode" in anger or grief, but any word for someone who will run away from their emotions is great. Trying to describe a character that's story makes this aspect of them a huge part of their personality.
Bert was _________ and Apartment 123 became a war zone when Ernie first started giving his attention to Rubber Duckie.