It's generally the habit of blocking feeling, unpleasant feelings you don't want to feel - you repress them - which then leads to the habit of all feelings starting to get blocked, as it's the action of reenforcing blocking of feeling, which you don't have the ability to control which would get blocked or not; The healthy thing in certain situations that are too tough or don't allow you to deal with them in the immediate or all at once is through suppression - though suppression turns into repression if you ignore it for long enough, or don't have the tools to work it out / talk it out with yourself or someone else.