My thoughts are jumbled, but I'll still try to share... A once friend of a friend used to frequently say, "If it [in reference to whatever topic at hand] were easy, everyone would do it." Perhaps that applies here too.
There's got to be books and books and books written on anger, I'm guessing. What comes to mind for me right now is practice. Like when you're in a situation that's becoming or has become heated, you learn to call a time out to cool down. And with time, you get better at preventing unhelpful escalation.
I also try to analyze my anger. I try to think through why I am angry. Do I have a personal problem that I need to get in check?
And/or has someone down something hurtful? What's the anger telling me? So, here I think anger is good. It informs us that we are in an unhealthy situation. The anger alerts us to something. I guess the key and harder part is to hold on to the message that we need to change an unhealthy situation while we let the anger go because its purpose has been served -- to inform or alert -- and to hold on to it is harmful and wastes energy.
Maybe it's helpful to think of it within the framework of energy conservation, that we (especially) can't afford to actively hang on to the anger.
I also feel though that I can't forgive someone who hasn't changed their harmful behavior. It seems that that behavior is always going to make me angry because it's hurting me and others -- so I have to remove myself as best I can from this harmful behavior, if the person will not stop their harmful behavior.
Maybe we have to try to be uber utilitarian though. Maybe anger is something like a smoke alarm. We need to pay attention when it goes off and investigate. But once we know there's a fire, we don't need a smoke alarm screeming at us. (Not the best analagy perhaps, but maybe the idea still came across.)
I think though that the people who treat us (and others) badly, I think they are the ones with the "psych problem". They can't accept the nightmare consequences of ME (as they now are), so they refuse to see reality and stay in a place of ignorance that makes them feel safe. Maybe ignorance is their drug of choice.
I've changed. I didn't ask for this BS change that is ME, but life smacked me down with it anyway. To survive, I've had to change and adapt. Lots of people don't like change though. And so it seems that they hold you personally accountable for this change that they did not want. And they find a way to justify to themselves that their unwillingness to change and adapt is the "healthy" way.
Ultimately, it's a betrayal. They betray us. Society, friends, family -- all know to say yes, yes I want to help sick people. But look at their actions. They can't handle what we carry every single day. They are the ones who are "sick" and weak even, actually. It helps me to think of it this way.
Every single day, they have an opportunity to educate themselves and to be a healing, healthy part of something huge. The ignorance and struggles associated with ME will not last forever. Humans will eventually solve this or greatly improve this situation at least (and the info gained in the process will most likely benefit people far beyond the ME community). In the meantime though, such nightmares cut to the core of what is really valuable in life and what is BS.
A good many people with ME aren't "living", we're "surviving". Our lives have been razed, and a lot of people don't want to face that. Again, they don't want to change...
With those who anger us though, the more intimate the relationship, the worse the betrayal and I guess the worse the pain and anger... If betrayal is bad and unhealthy, maybe we have to counter it by putting something good and healthy out into the world -- giving it to someone who appreciates it. Not squandering it on people who are most likely angry that we've changed and disturbed the image of life they're clinging to. (Still be kind to these people - but don't throw pearls before swine and such. But maybe when life nails them one day, they'll remember your kindness and grace under fire, so to speak.)
I personally would as much as possible, try to avoid the problem people. Seeing them, might even be a way of enabling their anger and bad behavior... I suspect we just have to live a very different life, and if they want to be a healthy part of it, they can. "Be the change you want to see in the world." If they don't want to be a healthy part of life, then maybe instead of anger, we have to pity them because they had an opportunity to be something beautiful in someone's world -- in many someones' world, and instead they chose to be small-minded asses. Reject their small-mindedness. Invest your mind and energy in something big and beautiful and healthy.
I think sometimes of Joseph Campell's Hero's Journey (though I have not yet read it). And it may sound odd, but I think we have to think of ourselves as heroes. We have huge, huge challenges to overcome. We have to be disciplined (which takes practice) and utilize the acquired wisdom of humans who walked difficult paths before us. If your life were a book or film, what would you be rooting for your character -- the "main" character -- to do, to be? To honestly struggle but to grow and then use this growth to help others? I think we have to try to embrace this. Maybe with betrayals, we have to accept that we'll have scars. But a scar is still healed. It's not a festering infection. And to let the betrayers' actions over-own too great a space in our minds -- maybe this is like a raging infection...
I didn't mean to write an essay!! And now I'm tired! I think though that it's just going to take practice to minimize the negative space that betrayal occupies in the mind. (It sucks, and it's hard. But it's better than the alternative which is living with the betrayal over and over again.) The betrayal doesn't have to or need to fully go away. It's a lesson learned. But we can't give it more room in our minds than it deserves. This is what I'm gonna try to tell myself anyway!