So @lavenderbagginshield asked for my headcanons regarding Thorin based on some tags of mine from this post. The thing is it's rather a series of interconnected headcanons, and I haven't my copy of the book handy to double-check myself about certain things so bear that in mind. Also this is like damn near pure angst. Scratch that: it is pure angst. And a bit long sorry!
So this is a post the dragonsickness, post the Hobbit, everyone lives AU Thorin — just so ye know where I'm coming from.
Firstly Thorin's lived through a whole load of Hell. His home gets burned and most of his people and friends and family when he's a kid; they go into wandering exile barely scraping by for a while and finally settle for a time... then his Grandad goes and disappears and gets tortured to death — which causes a war in which his brother Frerin is killed and there's also the rest of the devestating losses, though win the battle they did; they go into wandering exile again and settle in the Blue Mountains... then his Dad goes a bit mental and goes to try to retake Erebor and disappears: and he later finds out he also got tortured to death, and in the same conversation is handed the map and key to Erebor; he himself goes Questing, we know all the stuff that happened from then; and he finds not only must he live with the guilt of what he tried to to in his dragonsickness, but also how it caused a battle, out the other side of which he and his precious nephews come disabled [I suppose that's a side headcanon.]
I reckon that the reason Thrór and Thráin went goldsick was because they had one of the Seven Dwarf rings, but Sauron got that back off of Thráin when he was torturing him. I think Thorin went goldsick because there's something with the Arkenstone; perhaps when it's given back to him after the battle and after Bard and Thranduil get their fair dues, he notices himself slipping back into the sickness and in desperation smashes the thing with a hammer — at least I've seen such ideas floating around, and I like them.
Now all that disaster, grief, more disatster and grief, and even more disaster and grief must have a done a number on him.
I think first of all physically he's got to be disabled. I think he's had chronic pain since Azanulbizar. I like to imagine that by the end of all of that /\ he's got to walk with a cane, and has even more chronic pain, and both tendon and nerve damage. Now I also like the fanon that Dwarves aren't very ableist at all; but ablism or no you can't but grieve not being able to do things you used to with no bother, even when you find work-arounds there is a grief to the fact that now you must bother to find and do those when before it hardly took any thought — you do get over that eventually of course, or you make peace with it, but I don't think that'll be happening fast for Mr. Oakensheild. Also being in pain all the time is well, just that. Again I think he'd come to terms with it, probably much easier than coming to terms with the mental aftermath.
Speaking of: I reckon the goldsickness never 100% goes away from him. I think it's like a permenant gash in his pysche, to go with all the others. I think however that coming up out of the worst stages of it, and taking the action of destroying the yoke making him mad, made him become self-aware of what it was doing and continues to do to him. I don't think he's a very self-aware Dwarf at all, mind you; but he's had to become aware of his paranoia and anger and general spirals because last time he didn't check himself: he started a bleedin' war, distrusted his friends and loved-ones and made them all rather terrified of him, and nearly threw his fiancé off a battlement. And he vowed he would never do it again. So for him an attempt at self-awareness is a must.
The thing is just because you know you're being paranoid doesn't stop the thoughts from coming in and making you anxious, and knowing you're just being illogical will only make you feel even more like you're going mental. Just because you know there's no need to feel violently angry doesn't stop you wanting to smash things. Just because you know your emotions are irrational doesn't stop you feeling them.
And oh boy does Thorin feel them.
But then he has been feeling, usually horrible, for as long as he can remember. Long, long ago he learnt to try not to let on what he was thinking or feeling. I think again in the intensest moments of the goldsickness he just didn't bother even trying to hide it, but otherwise he'd rather shut his mouth and scowl and brood than say "Oh someone please fucking help me."
Partly because it's been so long he doesn't know he needs it. He's spent pretty much his entier life having to just keep going or die, and keep going to show the people around him that you can just keep going. I wonder how much he just shut up got on with it all because he was afraid if he didn't what kind of a message would that send to his people, to his friends, to his sister, to his nephews? I wonder how often he would comfort Dís or Fíli or Kíli or one of his friends, when every fibre of his own being wanted to scream and bawl. I wonder how often did he drag himself up by the bootstraps, ignore the agony physical and mental, and get on with the work that needed doing?
I wonder how, or more preciesly if, he can handle peace.
I think Dwarves, especially the royalty, are by and large religious. I think, however, Thorin wonders what kind of Maker allows His people to endure such hardships, and take to His Halls any that could not endure it? Thorin wonders if that is a curse or a blessing: blessing not to have to endure it all, curse on those left behind to endure it all still and endure also the grief. I think he's been told that Mahal doesn't control the fates of the world, but I think Thorin finds this a disatisfying answer. However I think he believes that maybe if he just begged Mahal hard enough, and was thankful enough for what he did have maybe it'd all get easier to bear. I think that belief does help him in some ways, it's something the cling to if nothing else.
I think however that he doesn't think he was Made to live in peacetime or Made to have happiness that lasts. I think he's suspicous of it. Waiting for it to get ripped from him, or for the joke to be revealed. It's harder to drag yourself up by the bootstraps and get things done when the goal for today isn't 'make sure none of my family or friends die' but 'talk to some people you hate about maybe drafting a proposal for a trade deal.'
Long story short: if we take Thorin too seriously we get a Dwarf who absolutely shatters to pieces as soon as he finds himself in permenant safety, peacetime, and potential happiness.
I think however maybe, maybe, he gets the chance to learn how to live in peacetime, learn to accept that he and his are safe now and he does not need to be permenantly on self-imposed watch duty, maybe he can learn to cope first and be happy later. I'd like to think so. I'd like to think he does it with the help of a Hobbit he married, and his sister, and nephews, and friends. And maybe the Dwarves' equivalent to a good few years of professional help because dammit he needs it, maybe Dwarves have healers for the mind?