You have good reasons to resent
I think at any given point, all of us can think of a dozen good reasons to resent someone or something in our lives. The reasons to hold on to our resentment might in fact seem ironclad. Resenting might even be morally and legally the right thing to do.
But carrying the weight of not just the resentment but also the justifications for it is good as tying a millstone to ourselves. We end up becoming bent-backed versions of ourselves, with faces permanently twisted into scowls. All there is to taste of life then is bitterness.
So while you are well within your rights to choose resentment, the question to ask yourself is this: what if I choose to let it go?