Stress, caregiving, and lack of support. Any ideas on how to cope?

Relating to Caregivers I have read so much about stress and am not seeing many ways to deal with it yet so I have many questions. Here's my situation. I have had anxiety disorder from my childhood on. I am taking care of my Dad (possible dementia and Magor Depressive Disorder) as well as my HF ASD Son who has OCD components and Anxiety. My physical health is not good. I have a rare cuvature in my spine, multiple herniation's, protrusions, that cause pain in my neck, back, and head. I needed my Father's assistance while I underwent intensive treatments for my spine. I did not want to put my Son at risk. I noticed my Dad having issues. IT took me nearly a year to get him somewhat appropriate treatment. His personality changed, he refuses to do daily tasks and at this point is creating more stress that physical help.
My Dad has called me names, belittled me, etc. I am VERY good with finances and he admitted he cannot handle them. HE owes over $5,000 alone on his Electric Bill from his own home. He wanted me to take it over. I have asked him to do small tasks, he first said he forgot. We then decided to have him write them down. He still claims to forget. I advised him to use separate notebooks for various things (finances, chores, etc.). He refused. In the past several months he has not made payment arrangements on specific bills that are behind, he let's them go accruing fees (I gave him numbers and had him write down what he had to do). I am keeping up with the current bills.
Do to the above he has created a plethora of financial stressors. There are thing cannot handle. I also think he is capable of making certain phone calls however he refuses. In the midst of these issues (usually at night) he can get angry, yell, and create chaos in my home. When he get's angry he is supposed to separate himself. He refuses at times. I have asked why he does not do a task on the list he says he does not know and will refuse to act when I remind him most of the time. There is more but I could write a book on his actions. The point is he creates a lot of issues, most of which are unnecessary.
To limit my stress I ignore some of his behaviors, some of the finances he has to handle that I cannot as usually it creates arguments. I cannot ignore everything. I am reliant on some of his help financially as well.
I have now gotten sicker. I was diagnosed with a stomach motility disorder casuign severe constipation on top of the pre-existing conditions. There are days I have to sue the bathroom for 6 hours on and off and cannot leave the home. My anxiety has gotten higher.
I contacted my case manager and advised her of my anxiety. She offered no advice. She feels my Father is not sick and is manipulating me. She feels he is miserable and is trying to make everyone else miserable. (that was the jist of ehr advice) I contacted my Psychiatrist who is new as my old one left the practice..The new one made a small med adjustment and advised me to try a partial program to ease the anxiety. It sounded good however it runs 6 hours a day and the intake counselor advised me I am not suitable due to my physical limitations.
I was advised my another agency to get a second opinion by another Psychiatrist. When I called on that today and was informed my case must be closed at the other office. It is looking like I cannot get a second opinion due to my insurance.
I do not want ideally to have to be on more medication. If however that is needed to keep my anxiety down I will go that route for now. It seems to be the necessary evil. I have a therapist appointment pending. Has anyone had their anxiety level this high and what have they done about it? I have NEVER been this ill in my life with it.
I am aware I should limit my stress for the time being. How to I do this without beign able to leave the house very often? I cannot change my Father's actions. Whatever is going on with him (he refuses to follow Dr's advise) I cannot fix.
I have been dealing with all of this for quite sometime and am afraid I am at burnout. Is that a possibility? If so what can be done about that? I am not comfortable putting this all here however, I feel left in the dark with my treatment. I also feel as honest as I have been, I am being told to "suck it up." I do nto understand why the new psychiatrist would recommend a non-viable option. She also made a comment about me being in the situation I was in as if I can just get out of it. I think that needs to be addressed with a skilled therapist after I get my symptoms under control.
Who here has done what to cope when the anxiety get's this high? Ideas would be great.