I agree with those who have said prayer, most definitely. A slightly adjusted serenity prayer helps...
God, grant me the serenity to accept the people I cannot change.
The courage to change the person I can.
And the wisdom to know the difference.
I use this version of the resentment prayer...
God, I have a this pentment towards X that I want to be free of.
So I am asking you to give X everything I want for myself.
Help me feel compassion; understanding and love for X.
I pray that X will receive everything they need.
Thankyou for your help and strength with this resentment.
I also like this prayer (the Do It Anyway one)
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’m kind, people may accuse me of ulterior motives. Let me be kind anyway.
Help me to accept that if I find happiness, people may be jealous. Let me be happy anyway.
Help me to accept that the good I do today may be forgotten tomorrow. Let me do good anyway.
Help me to accept that I may give the world my best, and it may never be good enough. Let me give my best anyway.
God, help me to remember that it is between you and me. It was never between me and them anyway.
There are also some great AA speaker recordings that deal with this area. Might be worth having a browse...
Search for "resentment" - AA Speakers & Tapes - RecoveryAudio.org
Also, don't pass up the opportunity to chat this through with someone in AA who has already worked the steps and seems to have a healthy sobriety. It's fine to just ask someone at the break or after the meeting if they have a moment to spare you to help you work through some stuff you're struggling with. I'm taking it that you don't have a sponsor yet, but if you do have one, open up and let them help you work through this. This is what the fellowship of AA is all about. Even further into recovery it's easy to get so caught in the vortex of an emotional dilemma that we can't see the wood for the trees. Often, as we talk it through, we start thinking about it slightly differently ourselves. We start to notice that we're choosing to omit certain things from the story (often a good place to look for 'our part' in the problem - or maybe that's just me lol) and where we may be adding in details that are our own 'slant' on things (that's where we can spot where our fears and ego are leading us by the nose - then again, as before, maybe that's just me, but somehow I suspect not. )
And remember, getting rid of our resentments isn't necessarily about managing to forgive someone. It may just be a conscious decision to accept the situation for what it is, and the person for what they are, and that neither are necessarily a reflection on us.
Wishing you all the best for your recovery and sobriety. Keep at it. This is very early days. It does get easier if we're willing to do the work.
BB