joeylittle
Sponsor
Seconding this.I think your in danger of overthinking things...keeping those messages and keeping on reading them is a vicious cycle that you need to break out of.
I think this is one of those situations where the "why" isn't necessarily going to help matters. Or, that you'll only be able to see the why of it once you've changed the behavior.
My advice would be to recognize it as a form of self-harm, and eliminate it as a maladaptive coping mechanism.
It starts with deciding to change the behavior. Get rid of the temptation to look back on these things - whether actually reading them or reflecting on them - by throwing out the emails. If it helps, write down more recent hurts and then throw those out as well. When your mind is tempted to go there, make a conscious decision to distract yourself with something else.
If you aren't willing to change the behavior, then that's a different issue....but you'll need to become willing to change it, before you will be able to.