hello~~~ i would love to recomand if you read story.. a few story from the author: kpoponly
her story is very refreshing and make you feel every setences and emotions of her character ...
the story is :
1)The Secret-Keeper
it is an angst, and romance story between gdragon x oc(kim haeri)
2) SCANDAL
the story is romance,idol life,angst and .the character is gdragon x taeyeon
3)the client
4)the real beast
5)just ...really?
eventhough you might didnot likes story but you must give a try to the plot and emotion the author have convey through the story...

http://www.asianfanfics.com/story/view/236678/longing-for-feelings-arrangedmarriage-drama-romance-sad-you-exo-kai
check this out!

you can read Flower of Despair by Dreamyflower. It's a nice story and full of meaning (*my personal opinion). Highly recommend :)

This author actually specializes in angst. I highly recommend you to check her out. Sure to brawl your eyes out within a few chapters :

http://www.asianfanfics.com/profile/view/1168576

All her fics made me feel so much sadness I couldn't move and started crying hysterically
Hope this will fulfil your request :))

Here's another one - My Last Wish:

http://www.asianfanfics.com/story/view/268501

Breath of life. Sehun ×Oc ff .Really sad it makes my sis cry for 4days nonstop every night

Here's one:

Till The Last Breath
http://www.asianfanfics.com/story/view/1161902/till-the-last-breath-i-would-love-you-angst-arrangedmarriage-you-jackson-got7-jacksonwang-wangjackson

I always love infinite angst stories.
1. http://www.asianfanfics.com/story/view/170521/starlight-tears-angst-hardcore-infinite-romance-woohyun
2. http://www.asianfanfics.com/story/view/928247/unforgiven-angel-angst-arrangedmarriage-fluff-iusinger-romance-woohyun
take a chance to see those, i hope you enjoy it as much as i do :)

this one is really good! i've reread for countless times already but still crying at the story. I hope you like kris so here you go http://www.asianfanfics.com/story/view/646515/unintended-drama-pregnancy-romance-marriage-sehun-chanyeol-kris

a one-shot angsty fic? hope you like kyungsoo ouo

https://www.asianfanfics.com/story/view/1074714

I'm sorry to have a cheap ads of my story here.
Do hope you will check it out if you don't mind.

Here's the link: http://www.asianfanfics.com/story/view/1056371/behind-the-screen-romance-chanyeol-chanyeolxoc-songkyungil

The Person Who Once Loved Me by prettysinggg! It's good! You should read it. :) It has only 25 chapters.

http://www.asianfanfics.com/story/view/1034298/maybe-if-i-skip-dinner-angst-anorexia-exo-xiumin-baekyeol-xiuchen-eatingdisorder

It is not an OC story and there are small hints of a gay relationship but they're so tiny and the focus of the story is really not romance so I'm honestly pretty sure that you wouldn't be uncomfortable with it. It's a Baekhyun and Minseok-centric story but idk. Oh well.
At least it's angst.

http://www.asianfanfics.com/story/view/1142691/final-call-angst-kyuhyun-romance-taecyeon-originalcharacter

I hope you will lke that