I don't know that to do anymore. My 18 month old son is constantly whinging, crying, angry and miserable, nothing makes him happy, he's been pretty miserable even as a baby but it's beyond out of control now. I wouldn't say there's anything medically wrong like an allergy, etc because he tends to stop as soon as you give him the amount of attention he wanted.
I give him toys to play with, he throws them, most of his toys are broken because he will throw them so hard across the room.
I give him snacks to pass the time, he throws them, he doesn't feed himself because I know he's going to throw it, every time I try to give him the independence to feed himself it ends up on the floor.
Give him what he wants, 10 mins later he will throw it away and then start crying about it, give it back to him, he'll immediately throw it again and cry more.
Put tv/music on for him, he's satisfied for 5 maybe one song then he's not interested.
Try to do sensory play with him like playdough, he throws it.
Try to incorporate throwing into a game, he throws the thing you're not meant to throw.
I could buy him all the toys and play all the games with him in the world and he will always go for the things he knows he 100% isn't allowed, leave your phone on the sofa for 1 second whilst you grab something and he will be at it straight away and will get adrenaline from you telling him to give it back and try to crawl away with it as fast as he possibly can. But even when sometimes I give him my phone, it eventually ends up thrown.
He's self injurious in his temper when you finally have to give in and just let him cry or when you have to tell him off for doing dangerous things (I've gotten rid of everything dangerous and he creates his own danger) he slams his head so hard against things that sometimes he even shocks himself and starts screaming even more because he's hurt himself, he headbutts me, the floor, anyone whose holding him, sofas, walls, drawers, tables, toys, his cot, anything. Mostly out of anger but sometimes he headbutts just to headbutt??? Other injurious things he does is hitting himself in the head and he also licks his hands in a rage.
He sleeps and naps perfectly, always has, from about 2/3 weeks old he's slept through the night and still does, and he's super gentle with animals and babies, he's very caring and likes to share (enjoys giving the dog his food and I mean, it makes him ecstatic, and he did try to shove a custard cream in my newborns mouth when I looked away for 10 seconds to be kind and share 
) the only time he's ever whingy because of being ill is from teething but he's not teething now. You can tell when he's teething or unwell because he actually hugs you and snuggles into you for comfort when he is, when he isnt he doesn't care about affection, if anything, he uses it as a ploy so you will pick him up, he'll give one brief "awww" then he tries to squirm out of your arms to grab the thing you pulled away from him or your tea, anything he's not allowed. Before he ever got unwell or had painful teething I never had a hug from him, I'd never experienced any form of affection from him and I tried to give hugs and kisses loads to him but he's just never interested. He does hug and kiss more now but very rare occasions.
I don't know what to do anymore, he is constantly MISERABLE, I'm at my witts end and so is my partner, nothing stops him from crying, throwing, being self injurious, etc, and I mean NOTHING. I love him to death and I've genuinely tried everything, we can even go out somewhere and he still just wants to throws, headbutt and scream, he's nice for about 2 hours of a day then is just incessantly screaming for the rest unless he's napping or sleeping.
Try to take him out and if he's not constantly moving then he's angry about it, but I need a break sometimes, I can't be moving 24/7 but that's what he wants.
Could it be ADHD? (I ask this because my partner (his dad) has ADHD and was diagnosed when he was 9) What could be wrong? Do I take him to a doctor? Do I talk to the health visitor about it? I don't know anymore, I feel like I'm actually being send crazy from the constant drone of crying that I'm surrounded by, surely that sends someone crazy eventually? I just want him to be okay and he's never okay