Need Help Post Care-Giving Parents

Hello,
I have gone through what was the most difficult two years of my entire life of 58 years, giving care to my parents here in my home. I now sit in the aftermath and I am overcome with grief, deep sadness and guilt.
My father took a bad fall back in September of 2015 and his overall strength and cognition would take a sharp decline over the 18 months to follow. Two years ago, I had to step in and move my parents to my home out of state, to provide 24/7 care to my father. And so it began...
From day one, care-giving my dad was incredibly demanding - beyond anything I’d imagined. My beloved dad had developed an irrational bathroom obsession and I could not take him enough times on any given day. My father was 175 pounds, and he could not support his own bodyweight. I had to lift him from either laying down in bed or sitting from the sofa using a transfer belt, 10-12 round-trips to the bathroom a day - plus in and out of bed, into / out of the sitting room. I was also charged with ALL other care-giving tasks with no relief or assistance.
As difficult as my father’s care-giving was, it paled in comparison to living with and tending to my mother in tandem, as she was completely “off of the rails” emotionally. My dear mother was unable to process the dramatic, woeful changes in her life and she was mad at God, my father and oft times me. I won’t go into too many details, but my mother became combative and lashed out at my father and me numerous times.
After roughly 18 months here, my father passed from his declining condition and my mother and I remained. Not two weeks to the day that my father passed, my mother took a big fall in the bathroom – shattering her elbow and breaking her wrist. She was in and out of 2 hospitals and short term rehabs – returning home in a 100% dependant condition. I now had to care-give my mother to the same extent as my late, beloved father.
To be clear, my mother was a beautiful soul, but she had a nervous / behavioral condition (heightened immensely when my father fell ill) and she was extremely difficult to live with or even be around. The relentless pressure I was under for roughly two years 24/7 without reprieve or aid wore my nerves to a nub. I felt depressed, hopeless - sometimes suicidal and most of all far too easily angered. In the late days of this situation, I found myself having a “hair-trigger” whereby I would start yelling and becoming very upset and agitated when my mother would push my buttons (care-giver’s syndrome?).
Early last month, I had overslept a bit and didn’t feel too well. I had to get my mother ready for the PT who was en route to the house, and I was pressured and rushed. While I was trying to get mom ready, she was driving me up the wall with rapid-fire requests and demands while I was performing individual tasks. I became triggered and in short order I was yelling, stern and rushing in a huff. My mother was trying to sit up from her adjustable bed and she reached for my hand. I refused, telling her to stop being weak and sit up on her own. She then said she felt faint and asked me to get her into the office chair in the room. I scooped her up and transferred her to the chair – she went limp and stared blankly into space. I thought she was undergoing one of her countless nervous “tizzies” and I barked at her to stop it. I had no idea that she was in her last moments here with me. When she didn’t respond, I called 911 but they were unable to resuscitate her; she passed that afternoon.
I am devastated having lost both of my parents within 4 months. I am further ravaged by the sudden unexpected passing of my beloved mother that afternoon, feeling overwhelming guilt for getting triggered and not being kinder and gentler. I never would have believed our last moments together would be as they were. I really loved my mother and I can never forgive myself.
I don’t know where to find some counseling for this and I currently have no insurance. Any ideas are appreciated greatly.