My third cat came to me with a birth defect that caused him pain. He then had to have surgery at 6 months old and then cage rest.
So the crucial bonding and socialising time with him as a kitten was when he was sick and in pain.
Through no fault of his own he was short tempered and took it out on my other two cats and myself when he got off cage rest and this continued for about 4 months until I decided I needed to do sonrthing about it.
I did some things that made a huge amount of difference and now the 3 boys are asleep on the bed with me as I type this. He is a mellow little angel.
The first thing that made the most difference was removing grain from his diet. I did a lot of research into nutrition and consulted the vet at the specialist hospital where he was treated.
This vet recommended a wet only, grain free, sugar free, high meat content diet.
This made a difference in about 24hrs. I recently had to give him some Felix and Sheba and he had his first fights with his brothers in months.
I recommend the site Zooplus. Their customer service and products are the best you can get in the UK.
I have changed all 3 of mine over to this diet and they have lost weight, their coats are shiny and they are all happier in themselves.
I feed a mix of Wild Freedom, Macs and Feringa.
I have also found that chicken, rabbit and poultry keep them in the best moods. Beef, pork and fish aren't the best.
Then on to supplements. These were recommended by the vet also, and he told me to get them on Amazon subscribe and save which is great.
Feliway Cystease capsules aren't only for preventing cystitis. They have a calming element that helps anxious cats.
I sprinkle one over breakfast and one over dinner daily (they can be opened and mixed with food or treats).
Secondly, Zyklene. I also mix with his food.
And lastly I have two plugins in my home and I do notice a difference when they run out.
I have the Pet Remedy one and Feliway Optimum (this is the best, Feliway friends did nothing for mine).
We have gone from a cat that would literally attack his brothers when they were sleeping and he wouldn't let me stroke half his body, to a moochie, lovely boy who is a cuddle monster.
Some of that will be socialisation and time. But I have noticed a huge improvement in my older two also, my implementing these changes.
The older two have never been aggressive, but they are calmer and happier now too.
In that time I have moved from the UK to Thailand and then I have moved twice recently and I credit those supplements and plugins with how they have been throughout.
They have had absolutely no issues or anxiety literally moving to the other side of the world.
It is an investment, and they take 30 days of consistent use to really work... But please give them a try before rehoming your cat.