Letting go is like anything else...it becomes easier with loads and loads of practice & loads and loads of time. There is also something to be learnt from those who are cruel, unkind, spiteful, and the like. The lessons are a beautiful gift that you give yourself for the burden of having to interact with them charitably, hahaha ;)
I would add, believe it or not, that my dad, who TBH is not a very nice person, has unwittingly educated me from almost day 1 in an awful lot of the dregs of humanity's baseness and in the bitter depths of intentional spite and cruelty, some of which he has disciplined a bit over the years and much of which he has not or only partially. And much of which he neither cares nor bothers about too much.
There are many, many times throughout my life when I realized consciously that dealing with not all but nearly every difficult person who's crossed my path was fairly routine due to having to interact courteously with my dad regardless of what he's said or done, and to learn to perhaps even enjoy a few moments here or there before it goes out the window per usual
And I have thanked him for that privately for that and in some honest discussions with mum and best friends, etc. Not him, of course, so as not to offend him, hahaha ;)
I may feel a twinge of mild disappointment at times (I am still only human) but peaceful acceptance on the whole is not bad, not bad at all.
Particularly for the peace of mind and the heart. I have once or twice been struck by how much some fathers seem to genuinely care for their children and most of all by the respect and genuine affection those adult children have for their fathers. And I have also been struck by how relatively rarely I have seen that sort of tight bond, and how unfortunate that is for everyone, including for the men themselves.
But for the most part, I simply accept that this is what is, and that my father is not as uncommon as humanity as a whole might prefer in his excesses and shortcomings, his self-absorption, his vanity, his immaturity, his loathing of commitment and obligation, and his obsession with sex and infidelity in defining his manhood. He is unfortunately a product of his day, and whilst certainly not the most sterling of the lot character-wise, truthfully he's not the very worst either. He married (apparently grudgingly but mum didn't realise) and grudgingly provided for us, same as many others of his gen did, LOL...and was a bitter, peevish, unfaithful, and spiteful man till the marriage ended many years later.
Perhaps when I am a father, in some other lifetime, I can be that kinder, stronger, and more loving man and father to my own children
As, I've only been a mother to date, that I can recall from past lives, and that's also what I'm working on for the mo
Maybe I'll put fatherhood on my bucket list for later. It would be very satisfying to add to the world in that way, since there is such an immeasurable and gaping lack in our world's cultures of mature manhood, one that doesn't rely on heavy-handed authority structures and domination of others, but yet still maintains the strength and purpose that personal discipline, integrity, and spiritual centredness bring.