As a therapist, I spend a lot of time telling people that it’s okay to have feelings, and it’s healthy to express those feelings. You can think of “bottling up” feelings like making a purchase on a credit card: you still have to pay later, and the longer you wait, the more interest accumulates. When we see someone have a huge outburst in response to a minor frustration, this is all the feelings from before coming out all at once.

This does not mean that we need to let out every emotion all the time as soon as we feel it, though! To use a personal example, sometimes in a therapy session, a client might say something that gives me an emotional reaction. It would absolutely not be appropriate for me to burst into tears in the middle of someone’s therapy, so I compartmentalize that feeling to deal with when I am not working.
Compartmentalizing is like buying groceries with a credit card but then paying it off before it accrues interest. The difference between compartmentalizing and repressing is that you go back and deal with that emotion in a healthy way before it has a chance to fester or build up.
Be mindful of how you compartmentalize feelings, especially during times of high stress. It’s tempting to bottle things up – I will feel better now if I insist that everything is fine, but in the long run, I will pay for it with interest later.