Look After Yourself!
I have come out the other end of looking after my elderly father who has now passed away. He was a stubborn proud man & it was hard dealing with his personality, although I loved him dearly. My advice is this - never loose sight of looking after yourself as this time in your life will not last forever.
Try to counter the negative experiences with something positive for yourself, even if it's just a movie, a picnic or a walk on the beach or by a river. My siblings were not supportive, so I became expert at 'self talk' & writing my feelings down, no matter how negative. Get some time off, that's essential.
I joined a women's social group & found it comforting to hear that others had been through similar experiences. I now feel satisfied that I did my best, while still trying to preserve my sanity & I still had enough of my life from 'before' to return to afterwards.
I am now working on the publication of my Father's autobiography - he was a Spitfire Pilot in WW2. Things are slowly returning to normal & I am starting to forget the negativity & frustration with the help of my family.