Sorry you had a tough day and took people so personally.
I too have really struggled with those 'justified' resentments, so I do feel for you. It is so important to work through resentments (even when they are justified) and kick them to touch - because if we don't do so, they pose a threat to our sobriety.
I have recently added this to my morning meditations to help me deal with the things that I know I could easily get resentful over as my day progresses (I adapted something I read that was attributed to Mother Teresa. Since then I've seen it again, attributed to someone else, so I'm not sure of the actual source)..
God. help me to accept that people may be unreasonable and self-centred. Let me forgive them anyway.
Help me to accept that if I am kind, people may accuse me of ulterior motives. And let me be kind anyway.
Help me to accept that if I find happiness, people may be jealous. And let me be happy anyway.
Help me to accept that the good I do today may be forgotten tomorrow. And let me do good anyway.
Help me to accept that I may give the world my best, and it may never be good enough. And let me give my best anyway.
God, help me to remember that it is between you and me. And it was never between me and them anyway.
I also try to use the resentment prayer as soon as I feel that fizzy, bubbling, heat of a resentment forming. It is surprising how much it can help. It's a bit like one of those carpet stain removers though. I often think it's worked first time and forget about it, but as time passes I realise it's still there and needs a second application. Or a third, or a forth, It always works in the end though...
God, I have a resentment towards X that I want to be free of.
So I am asking you to give X everything I want for myself.
Help me to feel compassion; understanding; and love for X.
I pray that X will receive everything the need.
Thank you God for your help and strength with this resentment.
(You can feel free to insert expletives and use derogatory pet names for them if you feel the need. It will still work the same).