The phrase "to repress those emotions" means to hold back or suppress one's feelings or emotions, not allowing them to be expressed or shown. Full definition
There's a diversity of opinions about this, but the best explanation I've ever heard is that a panic attack is a ton of repressed emotion bubbling to the surface in full force. (mindbodygreen.com)
This could be a whole different blog post, but the thumb sucking has to do with repressing emotions, which means he needs to do some emotional releases (crying), but that's for another long blog post. (katesurfs.com)
If the lack of fresh air, good food, and stimulation has your students feeling depressed and lethargic, try Breath of Fire, while hip openers can help your students release repressed emotions. (vikasayoga.com)