In search of a novel that deals with Self-loathe and loneliness.

Hey,

I search a preferably novel, best written in the perspective of the affected maincharacter.

Idk how to exactly put it into a sentence so l just list what im looking for.

The book should deal with:
Self-loathe and Self-pity,
The feeling of beeing abandoned by others, backstabbed,
To not show your feelings/yourself to not drive others away.
The book should show that it is ok to show weakness, to not bottle up and accept help.
That you dont have to do everything alone. Self-sabotage

Basically im searching for a novel telling the story of someone like that, how he/she manages to break out of that cycle. The protagonist learns to be not dependant on others, that its ok to be themself and learn to accept and maybe love who they are and learn that their flaws are good to have.

Best case would be to show the lowest point of a human, maybe to such a degree that he thinks of doing the unspeakable. That the road there is hard, harder than doing nothing and staying were you are. And then show the end with huge contrast with the Protagonist beeing independent and on the way to happiness

Im posting here because i pretty much dont know how to fit that description into a google search. I do find a lot of books with advise for youself or how to help others dealing with problems. But i really want a novel if possible. Because i think storys are sometimes better than educational books for some people because you can see the world in the protagonists eyes.