Can somebody help me

I take every single disagreement and mild piece of criticism incredibly personally. I don't ever react to the criticisms and disagreements bombastically in any sort; I don't violently lash out or verbally harass or express vehement disagreement, but instead I completely shut down. I don't speak, I feel a pit in my stomach, my thoughts go wild, my disposition and thoughts towards the person that whom I disagreed with turn silently bitter temporarily, and I overall feel like a bag of shit for hours on end and I hate every moment of it. This has been happening for years and it destroyed a loving relationship of mine and has ruined many days that should have been joyous if not for somebody saying something that rubbed me even slightly the wrong way. Does anyone that has had a similar experience have even the slightest clue of how to remedy of this? I have pondered on the possible reasons for this awful tendency for years and have found nothing that has helped. Any and all assistance would be appreciated :)