That sentence inside: “why me?”
The same thing, and when someone else does it there's no problem. The same effort, and a different result. You know life isn't fair — knowing it doesn't move the weight in your chest.
Sometimes you say it out loud and then feel small for having said it. Sometimes you say nothing and it just sits there.
The awkward thing about resentment is that the person it usually injures is you.
What may be going on
Feeling something is unfair usually means you once believed sincerely in an order: effort is repaid, kindness is met with kindness. Resentment is the response when that belief is let down.
So it isn't small-mindedness — it's closer to a disappointment that hasn't been acknowledged. Being told not to think about it so much only sinks it deeper.
The first step in loosening it usually isn't forgiving anyone but letting yourself admit: I do feel wronged.
Essences that may fit
You don't need all of them. See which description comes closest to how you are now.
Willow
Resentment, feeling wronged
Resentment collecting; feeling short-changed. It doesn't accompany you towards magnanimity but towards seeing the grievance yourself first.
Holly
Envy, anger, suspicion
If there's clearer anger or suspicion in it, this one comes closer.
Vervain
Over-zeal, the missionary streak
If you carry a strong "this is how it should be" and keep wanting others to understand, look at this one.
One small thing you can do now
Say "why me" inwardly once, without pressing it down.
Afterwards, notice your shoulders, jaw or chest — resentment usually lives in those places.
Let that place ease a little. Not to make you let go — just so the body doesn't have to keep holding it for you.
When you're too full, too tight, and need to loosen
Waiguan SJ-5 · Outer wrist