Looking for dramas with a FL that is serious/subdued

So I recently watched the kdrama My Ahjussi and I can't move on. No amount of praise will be enough. Then I watched the movies better days and that was pretty similar in tone as well. So I'm looking for something with a female lead who has a dark past or currently going through hard stuff but isn't chipper about it. I have nothing against happy go lucky female leads but I'm just not in the mood for them right now. I want a female lead who is bitter, angry and a male lead who also needs healing. Also I would prefer if the leads had a bit of age gap (not necessary though) I like it when the male lead is a little older than the female lead but not a jerk. I'd also prefer if the female lead is between 18-25. Since I'm 24 I find it easier to relate to characters in that age group.

Can someone help me out here? 

 Vampirehunter007:

So I'm looking for something with a female lead who has a dark past or currently going through hard stuff but isn't chipper about it. I have nothing against happy go lucky female leads but I'm just not in the mood for them right now. I want a female lead who is bitter, angry and a male lead who also needs healing.

The FL isn't exactly bitter or angry, but has a difficult past, is serious or subdued and not chipper, and the ML needs healing:

• Just Between Lovers
• The Smile Has Left Your Eyes
• Because This is My First Life

The FL has a difficult past, is serious and not chipper and maybe a little angry / bitter but also is older (also the ML is a mess but definitely does not get healing):

• Misty (the FL's past reminds me of My Mister)
• Empress Ki
• Time (the FL becomes very angry / bitter / not chipper after her sister dies, and the actress was 26, so not much older than what you're looking for)

 AH :

The FL isn't exactly bitter or angry, but has a difficult past, is serious or subdued and not chipper, and the ML needs healing:

• Just Between Lovers
• The Smile Has Left Your Eyes
• Because This is My First Life

The FL has a difficult past, is serious and not chipper and maybe a little angry / bitter but also is older (also the ML is a mess but definitely does not get healing):

• Misty (the FL's past reminds me of My Mister)
• Empress Ki
• Time (the FL becomes very angry / bitter / not chipper after her sister dies, and the actress was 26, so not much older than what you're looking for)

I've tried both just between lovers and the smile has left your eyes

Don't hate me but I absolutely detested The smile has left your eyes :') I know people loved but I guess it was a case of its me not the show. I want my male leads to have certain morals. I like grey characters like the ML in that winter the wind blows, but this one was....all black for me. There was nothing that endeared him to be and I lost respect for the FL when she started dating him because of the whole dating the best friend first angle.
I have come across misty several times but I dunno somehow I've never actually wanted d to watch it, maybe because its about reconciliation between two divorced parties and I dunno how I feel about that.
Might give just between lovers another try though 

No I don't think the Characters have to be older to have gone through a lot. Both better days and my ahjussi had younger characters.
Save me sounds like it'll be right up my alley so I'll watch it.  I Don't  mind if the two leads don't have a defined relationship by the end. I can imagine my own happy ending for them. So I'll definitely watch it. Btw is the lead played by woo do hwan or ok taecyon?

I feel you about My Mister. That was one brilliant Drama. 

Female lead has a dark/painful past and is somewhat subdued in character:

• Mars - FL really really has a very very very painful last and both MC are college student
• Live - same with above, FL has a very very painful past. The characters are around their late 20s in age
• Miss Ripley - FL has gone through hardship and is out to live her life for herself. And to get ahead for herswlf even if it means making lies as her way through life. Leads are in the 20s. 
• Kingyo Club - short drama set in highschool. FL is quite shy and calm. Though this is about a bullied student. 

Very calm and collected FL:

• My Daughter Sooyoung - long family drama, with FL going through hardship in living and isnt chipper and candy type on her circumstance. She is kinda bitter and hard hearted especially towards her father. Though ML is quite arrogant and doesnt really have any hardship or much healing on his part. 
• New Tales of a gisaeng - FL is very serious and calm with some painful birth history. Leads are in their early 20s, with ML older by about 1-2 years
• Thousand Days Promise - very strong and collected FL. Sadly the ML was a little weak especially at the beginning, but i think he was written so to highlight the inner strenth of the FL. 
• Goodbye to Goodbye - the mom character is the one who is like the character you are looking for

@Czakhareina

Wow these look pretty nice! Mars and new tales of gisaeng I've already tried.

Regarding Mars, I didn't like it much. There were several reasons

1) I felt like the ML seemed to have only one thing in his mind and I get that it was kinda the whole point but I found it distasteful after a couple of episodes 

2) the FL fell in love too fast. She also got comfortable around the ML a little too fast. Considering her trauma, I expected her to take a looooong time to fall for him. But it was almost insta love which seemed a little hard to believe 

3) more than half of the show was about the ML. His past, his trauma, his races. By the time the FL's side of the story started to open up, I was bored. I had started the drama to watch how the FL dealt with her trauma. Instead we see her helping the ML with his trauma with hers being only hinted at for most of the show. I find it unbelievable that someone who had not healed herself and was still traumatized, was able to give her all into helping someone else heal with no help from anyone regarding her own wounds.

The rest of your list sounds pretty interesting, I'll try them :)

Thankyou everyone, for the amazing recommendations :)

@vampirehunter

About Mars, i guess that could be said about mars. my focused was solely on the painful part about the FL lead that you are looking for. Definetely far from Jian from My Mister. Though personally I did Love it though ita been such a long time since I watched it. 

Though from my list, i definitely recommend you Watch, Miss Ripley. Probably nearest Jian in somewhat than most the leads in the other dramas I mentioned. 

Or probably Live, thaugh the trauma focus takes a while before it gets revealed and not a major major plot device, since the FL seem to be well adjusted given all that she went through. 

Also try Hateful But Once Again. FL is career oriented over achiver who is backed into a corner because of the ML's mom. with her career hanging on the line, she agrees with the ML mom's deal in taming the wild playboy ML. 

ANd Kenja No Ai. FL has dark past and set on revenge. These one has the FL wayyy older then the guy, and this is dark and tragic end. Not healing whatsoever. 

Lastly, i havent watched this drama (been meaning to, but i still have a lot in my to watch list), but i think you need to check out Krong Karm. I dont know why but I feel like this probably will fit what you are looking for. Though I would probably be wrong.