I think emotional exhaustion is a side effect of trauma. I am not sure if ptsd is required but I know I've been hit with a thought or two that has major physiological effects. It only last a minute or two but the side effects last for hours and sometimes days. I had to work through the beginning of my journey. I was in no shape to be living with anyone. I just wanted to be left alone. I picked up trash for a year in an apartment project because I got a discount and they took the rent out of my pay.
It wasn't legal but every other week I was able to buy a dime bag and if I was really lucky, I could buy a six pack of whatever was on sale. Coke or Pepsi. I couldn't afford Tylenol much less prescriptions but I don't believe I would like them either.

I wonder if you could use your ssi and go to college or a trade school? I'm not talking about a bunch of book learning but maybe something that keep you busy. Blue collar. Welding? Carpentry? Truck Driving? Anything to focus on while you find a way to work through your trauma?
Might even find a friend or two in business associations.

I am not saying this will work for you~ I just wonder because when I get physical, I am not as emotionally exhausted. Yes, it still kicks my *** but it's a different exhaustion. My way of doing things could also be why I'm still here~ I failed to fully recognize my experienced.

I wonder if there's a middle ground. I really hope you don't give up on finding a therapy/therapist that works for you.