"Friend, I'm honored and glad that you asked. I do feel I have a view worth sharing, but of course you'll need to decide its applicability and validity for you.
Most of my life to date I'd be deeply impacted by mean or cruel behavior directed toward me. But not, thank God, at all for 8 years or so now. Zero. My Heart hasn't hardened at all in that time, quite the opposite. But my Understanding of Life has grown ever so much.
Here's how the breakthru for me came. Someone had been just hideous to me, and the thought that came to me was - 'Uh, under what circumstances would Teresa of Calcutta (substitute your own personal hero of Humanity) have behaved that way to me?' 'UNDER NO CIRCUMSTANCE, EVER.' Immediately what clicked was that the behavior was clinically "sick," "ill...." I happen to be trained in psychology so understand that I mean "clinically" sick; I'm not throwing stones. Well, in seeing that I was receiving sick behavior, two things happened within me then, and since in such situations: 1. I no longer took it personally, which if I did, would paralyze me with hurt, rage, self-doubt..., and 2. It put my relationship to the inflicter in perspective - they were sufficiently unhealthy that a "healthy" relationship with them was obviously impossible, massively unlikely, unworthy of the time and effort....
Soooo, with all this did I then, and do I now in such situations respond instead with a sense of superiority? Does a good MD feel superior to a sick client? NO! But with the clarity I've just outlined to you I'm able to move on emotionally to the Life of Service where Joy is to be found, and not get bogged down. And, I've learned the humility that Jesus had, "no one comes to me except that the Father brings them." Such sickness that can be so hurtful IS NOT CURABLE DIRECTLY by us. It just isn't. AND IT FEEDS ON THE ATTEMPT BY THE WOUNDED PARTY TO HEAL IT! Sooooo, I just move on. If Our Father, Fate, Chance softens / heals the heart of the wounding party at some future date, YAHOO, I'm there to celebrate! But I leave that in Our Father's hands, and move on, realizing that by refusing to get derailed by cruelty done to me, and devoting myself to folks that desperately need, and can absorb my Loving service, I'm being the Light that could possibly lead to a regrowth of Humanity in the person that was horrible to me.
I don't know if this is helpful to you at all. If it is somewhat helpful, but provokes another question or so, please feel free.
Your brother, sl
ps: Of course, with all I've said above, of course this was enormously hurtful to you at the time, but I think it needn't be hurtful going forward.