Hello CapK, and a warm welcome to the site.
When you are in a situation like what you have told us, the years are definitely difficult to cope with and to try and understand why any of this happens, you struggle to find an answer which you are unable to sort out, and to be the rock, you need to try and interrupt what's happening around you, or as someone has spoken to about.
This is certainly not easy and fear situations you feel required to be involved in, just as much as you only wished you didn't have to, but never the less take on this responsibility.
I am so terribly sorry for what's happened and being the rock, doesn't mean you have the answers to help these people, sure they may want to talk to you and in your endeavour to help them, you have done the very best you could to try and guide them, but they need to consult someone who is experienced in mental health, then that's how you can then support them.
Now it's time you need to look after yourself because trying to be the rock has affected you in many ways, your sleep, panic attacks and whatever else may be happening that you're not aware of, but affecting you in different ways which now means you need to consult with your doctor.
You have to stop being the rock, because what you say may not be your best advice only because you aren't well enough, and even listening still puts you in the same position.
I'm just wondering whether you are able to move away while you are getting the help you need and if you are working then ask your doctor for some time off so you can get yourself back to how you were originally, except for the assistance you have provided.
Please get back to us when you're available.