I read Metamorphosis some time ago, but heard that Letter to His Father was even more personal, so I decided to give it a go. This won't be a traditional review, as I use mostly quotes from the book to show it.

"Dearest Father, Recently you asked me why I maintain that I'm afraid of you. And, as usual, I didn't know how to answer, in part because of my fear of you; and in part because my fear rests on so many details that I couldn't even have discussed half of it. And if now I attempt to give you an answer in writing it will still be far from complete: because I'm still hindered by my fear, and all that flows from it; and because there is far too much my mind to remember and consider."

The start of the letter sums up perfectly what this short book is about, and how complicated family can be. Later on, Kafka writes: 
"And for years I was tormented by the thought that this giant man, my father, could almost without reason come to me in the night, and lift me out of bed, and leave me on the balcony: he was my final court of appeal, and for him I was such a nothing." 
and; 
"And I could never understand why you were insensitive to the sorrow and shame you inflicted on me with your words and judgements - it was as if you didn't sense your own power."

"Your extremely effective and, at least with regard to me, never failing educational talk consisted of: abuse, threats, irony, a mocking laugh and peculiar self-pity."

"But it is true that you barely hit me. Yet the shouting, and your reddening face, and your braces being torn off, and the positioning of the chair back, were almost worse. They were like preparations for a hanging. But a hanged man is dead and all is finished. Yet if he has seen all the preparations, and the noose is before his face, and then he hears about his reprieve - he is left to lament his existence for the rest of his years. And I thought about this many times when in your opinion it was clear that I deserved a beating, but by your mercy I escaped - and I was burdened with guilt. On all sides before you I felt guilty."

I'm honestly at a loss of words. The quotes speaks for themself. We all deserve better.