I am so very, very sorry that you are in the situation you describe. You have been on this Forum much longer than I have and have helped more people so I don't know if I can be helpful to you.
There is something that helps me a lot but to be quite honest with you, many people have told me it does nothing at all for them.
Sometimes things that really help one person are totally worthless to others in the same kinds of situations.
I have a kind of "mantra" I say to myself when the stress of past and present traumas and difficulties are crushing me from every side. What I say is: "Could be worse, but isn't worse, thank goodness." Or if it is about things I fear in the future, I say to myself: "No matter what happens in the future regarding work, relationships, health and so on, I will still be able to say: "could be worse but will not be worse, thank goodness.' "
I get caught in a kind of "could, should be better" frame of mind. It makes me sad and ramps up my anxiety to great heights and even leads me to have panic attacks and rolling panic attacks.
I find I can disarm this with "could be worse but isn't worse" frame of mind. I could be worse, but am not worse. Other people could be worse but are not worse. Things, situations and events in my life and the world could be worse but are not worse, thank goodness.
I know it must sound crazy, but reframing my mind to gratitude really lowers my anxiety and unhappy and distressing feelings.
The worst I've ever felt in my life was when I had life threatening food poisoning that caused my to throw up constantly and without any pause or relief. I felt so, so sick and bad.
Now when I feel nervous or bad about something in my life, I think well at least I am not suffering from that food poisoning right now. And it helps me.
I am not on fire. I am not starving to death. I am not stranded in a desert without water and facing a slow and painful demise. Thank goodness!
People have told me that doing what I do has helped them but many more people have told me that it doesn't do a thing for them. So I am only sharing it with you in the hope that maybe you are one of the few who can benefit from it.
Hopefully other members here will have better words for you and more helpful words than my poor words.
It is awful beyond words when so many things join together and threaten to crush one. Pressures at home and work and everything else can be crushingly heavy.
PTSD in particular is crushingly heavy to bear in my experience.
I hope you are able to find things that really and truly help you. So sorry you are suffering!!