Her bf is just a jerk and she ends up alone

It's got everything you asked for, in terms of girl with traumatic past (rape) that leaves her broken and afraid of men. She leaves her old life with her estranged mother and friends and starts living on her own. Here she meets a boy and they start going out, however I haven't read the end so I'm not sure if the rest of it pans out the way you want it to

This fits in terms of the being broken as the series goes and then she attempts suicide, and they break up. Whilstthe ending is tragic, its not in the way you had it

Most of the time in the manga it centres around 2 people that are loners, and whilst the woman is semi broken from past experiences she manages to keep it together for the most part of the manga. However a certain event (its extremely graphic btw, just a warning) makes her even more broken and ends in one of the scenarios you asked for

The main character is broken because of a past event involving a friend and though she does get a couple of guys trying to coax her back to her old upbeat self she generally lives like a loner. The manga isn't complete so I'm not sure what direction its going to go, but at the moment there's a possibillity she'll be killed for her past mistake

Most of the time the lead character lives, not as a loner, but alone in herself because she has to be a bodyguard to a rich madam. She falls in love with a guy and he changes her but due to her circumstances they have to be apart and she falls in love with another guy in the interval, but towards the end the twists and turns end with her forgetting a lot of what happened, broken in a sense and living without her original love

the ending really goes with the first example. She ends up with a great career but marries another guy. But I think it's the guy who rather brings her down...

it's the dude that dies.

attempts suicide, and gets saved by this dude. I think she dies because she has an incurable disease that gave her a low chance of survival