Elder sibling recently Dx'd; I'm struggling with coordination of relevant professionals

Hi all, I'm new here. I have a much older sister in her mid-70s (one who I hardly knew growing up) who lives in another county, about an hour away—still in her own apartment. The only other family member is our brother, closer in age to her, who lives a bit closer to her, but is rarely involved. As I agreed years ago to be an emergency contact and health proxy, I became her distant caregiver-of-sorts by necessity when she started to suffer memory decline and, ultimately, lost her license/car. She assigned me as her DPOA and UHCP. She eventually got a Dx from a neuro at a memory clinic about a year ago—"suspected ALZ, early-to midstage"... nothing more specific than that in the follow-up summary. So I am basically all she has for support (she had many friends in her area, but boy, they disappeared fast). Her county does not provide transportation (at least, nothing someone with her memory issues can use), so I drive to her home and take her to her various medical/dental appointments in a tri-county area, as well as grocery shopping/errands weekly, and out to lunch and recreational outings on a regular basis. I'm also her go-to help whenever she has technical issues (frequent), and now even bring her laundry back to my house to wash/fold/return because even that has become too complicated for her.
If you read between the lines, I'm sure you can probably sense that I'm overwhelmed. I have a husband (has his own health issues) and we are empty-nesters. I am also still working. Thus, I'm finding it challenging and frustrating to find the answers and support I need, which lately has revolve around getting a handle on her financials, and understanding how to fund assisted living—and how long we can stretch her modest savings and meager pension.
I feel like she needs an elder lawyer, financial investment manager, and tax advisor rolled into one. This has been a roadblock for months now. Meanwhile, I'm concerned what will happen to her if she isn't placed in a proper assisted living community (with option for transition to MC) in the next 3 to 4 months. Living in my home is not an option, even if I could manage to care for two challenging adults at once.
Neither the memory clinic, social worker, nor the local support agencies have been able to provide the support or answers we need. Meanwhile, I cannot sleep through the night because I'm always stressing over the situation, and feel that my own health is deteriorating.
My apologies for rambling. Thanks for letting me get that off my chest!