One thing I think AA / NA does exceptionally well is to break down the concept of resentment into its component pieces, and teach/lay a different path out. Clearly, their focus is on addiction, so there are some things that won’t apply (unless you struggle with substance abuse or addiction) and other things that are come at quite blithely / are more footnotes to addiction, that are extremely difficult for people with PTSD or don’t apply at all (like ‘what was your part’ in a victim crime). But whilst most resources have single-type answers for resentment? AA/NA reeeeeally does break it down into several dozen smaller pieces, each to master, and reshape.
Just as an example? One of the pieces resentment gets broken down into is “The Triangle Of Self Obsession”... with resentment (past) anger (present) fear (future) creating a cascading effect, each feeding into the others to keep them spinning in either a perpetual motion machine, or any of those three things kicking off the other two... so a person isn’t able to ever really deal with one piece, before the next one takes over. (Until one learns how to).
^^^
This particular area of AA/NA recovery? (4th & 5th steps) Is strooooooongly cautioned against doing on your own... because most people use both the pieces AND the tools to beat themselves up with, rather than to help themselves. Which is also my caution. If you decide to use addiction recovery resources on resentment (fear, anger, guilt, shame, self obsession, et al)? Like learning to use power tools, It’s best done with someone who can keep you from cutting off your fingers or an arm, just switching the machine on.