Any sort of resentment that any of us harbour, does harm only to ourselves. Unless we can share those feelings and 'get it off our chest' without causing irrevocable damage to our relationships then I find it is best to let thing's go. Someone suggested writing a letter but not posting it, that sounds like a good outlet.
Not resolving your feelings hard though that may be, only serves to eat you up, and spoils your relationships, with people who are ageing and once they are gone, you are left with those regrets, or unresolved hatred which overrides and overshadows the fact that they brought you up, nurtured you loved you, saw your first of everything, and no doubt your Dad gave you away at your wedding. You don't say if you have children, but it may also be they have been good Grandparents, there is good to be found in your relationship with your parents. I would have regrets for wasting that time with them because I harboured a resentment. So for me it would be either bring it up and discuss it or let it go. Clearly the financial issues have had a deep effect on you, and you can only see that you felt unhelped by your parents during what clearly was an awful time for you. Have you considered that our parents are not obliged to help us financially? The other aspect I don't see in your post is, did you ask for assistance? There is so much we don't know, so whatever our input, only you can decide to free yourself of this resentment.
As for the advice to admit your parents are mean B's well, consider that might not be the case, they may be afraid of leaving themselves dependent on you or other family members later in their lives if they reduce their savings now. Not everyone is capable of supplying their children with financial aid, maybe all they can offer is emotional support. Not knowing your situation fully makes it hard to offer support to you, merely share what we would do or what we think we would do in the circumstances you describe.
I should also say, that we have some friends, who on principle their words not mine, will not assist their children with cash in anyway. They have taken the view that they are raising equity from their house and they are spending it. Nothing will be left for their children. Not that they don't love them, but they believe that this is their lives and they are living it with their hard earned money, and liquidated assets. It is not my way, but I can see their view, to a point.
I sincerely hope you can find a way to feel better about how you feel towards your parents.