I should have said "It CAN make them unbearable to be around". It was too sweeping a remark.
I think that all of our character traits are in us - the nature argument. Twin studies seem to back that up. But those traits can definitely be strengthened or lessened by nurture.
Did you ever hear the case of the triplets separated at birth? In a cruel experiment, three baby boys were split up and put into different types of homes, with different types of parenting behaviours (and I think one of them was also a poorer family, but it's been a while since I watched the video). The scientist involved deliberately chose people who had already adopted kids so he had a baseline for their parenting. These baby boys were never told they had brothers.
As they grew up, one of the young men started college and was greeted on campus by people who thought he was someone else. They quickly got in touch and realised they were absolutely identical. Their story was on the news and that's when the third triplet discovered them.
At first, of course, they were delighted to meet up. Later, problems grew. One of these poor young men killed himself. The other two, though they all had similar personalities and were all struggling, were resilient enough not to do the same.
The original documentary was called Three Identical Strangers, it's probably available on YouTube and there are certainly videos discussing it on YouTube.
Anyway, I only bring it up to say that although we have character traits which are literally bred into us, environment can play a big part in how we develop those traits.
To be clear - none of what happened to you was your fault. You are not to blame for any mistreatment you experienced. Children in particular cannot ever be blamed for anything bad done to them. No matter how difficult a child is (and yes some can be) they never, ever deserve to be abused. Adults always have a choice not to hurt chldren.
Well done on raising resilient, healthy children. It's not easy, is it, when you have your own struggles?
I had therapy. I also always had a "Fuck you" attitude. I rarely blamed myself for the bad things that happened to me - I put the blame solely on the perpetrator - well at least as I got older, perhaps not so much as a small child. That is just my character, and I thank God for that. I am an imperfect person with a temper, but I am also far better than a lot of the humans around. I am just me, and that has to be ok, because it's all I can manage.
If you have not seen a therapist, you need to do this. For you. To have someone who will listen without fear of the implications of telling them, and to spare others the pain and the burden of trying to help you when they are not trained to do so, do not have the skills, knowledge and perhaps do not want that burden.
You could live another 30 years, none of us can change what has happened, but we can make today, right now, a better place to exist in.