How to help anxious/angry daughter?

We've had a rough road for past 1 1/2 yrs since my daughter's temporal lobe epilepsy became intractable. She's a soph in HS, great student, but struggling more this year - sclerosis on hippcampus has caused memory deficits. We've also had ongoing insurance battles for Onfi coverage and mental health treatment. Spent 4-5 months with a below-average therapist last year that gave more aggravation than good results. She's scheduled for brain surgery in three weeks. (stereotactic leads placed thru burrhole + one surface grid placed via craniotomy - laser ablation about a week later after seizure foci is localized). Between her school, an extra-curricular activity, insurance appeals, my (and husband's) work schedules, needs of other two kids, and the unreal amount of appointments and tests to get ready for brain surgery, she had not had any good talk therapy or group work with other teens with illness/disability. I'm a teacher and husband is police officer with weird hours, so I am the 99% caregiver. A lot of my daughters friends drifted away some as her epilepsy has grown worse and she has done some self-exiling. My daughter's angry/anxious days have been more and more frequent - to be expected of course! She is attending school on a very light academic load until day before the Wada test 5 days before surgery - she'll stay home then until she's admitted for 1st surgery. Her Wada test day is when I start FMLA. I know that I can't change any of this or make her "happy." I try to brighten her days with something, even just a treat in lunch or a new T-shirt or book. People who've never been in this situation keep advising me to "take care of myself" - right. I still get some exercise in as best as I can, but making it to all of my daughter's appointments, making it to work, and keeping the house going is all I'm capable of. When my daughter has her bad days, she directs her anger at me, obviously since I am the safest person she can do this with. She's starting to not let me comfort her, and is getting irrational about understanding some logical things - also understandable. I guess I'm just hoping to keep up the strength to get through tomorrow, the day after that, and so on. I wish I knew how to better respond to my daughter's stress and anxiety. Of course the nearest parents' group is a one hour drive away at 7:30 on weeknights. Any words of wisdom are most welcome.