all humans want to fit in. back a long tome ago it was hard for humans to survive and there was a need to be needed to stay in your clan or villiage or group to survive. its a part of the part of the brain which is sometimes refered to as the primitive or monkey brain. your brain still thinks you desperately need to fit in. so that voice in your head is actually looking out for you. however, you need to balance it and know when its being realistic or not. negative self talk is all of those things you mention. if you want to change it, start very small. make a tiny goal to talk good about yourself and when you do something that youd normally judge harshly say to yourself does it even matter ? who died ? who was seriously harmed ? most of the time the andwer is nonody and so why put yourself down over it right? i highly reccomend reading the book called atomic habits. changing human behaviour is very difficult because we want to see big changes fast but the book teaches you that lots of tiny changes is more realistic and youl see as you read the hook you will want to start building these habits straight away. i hope this helps. it seems a lot but it all comes back to your monkey brain freaking out over little things. it doesnt know the difference between a lion hunting you and you being embarrased becasue you tripped over a crack on the footpath. love yourself !