Looking for a tv show like moon lovers that will make me cry for days 

Mother is great, strongly recommend it. There's also a japanese (original) series:
https://mydramalist.com/312-mother
I've not watched it, but it's also great I've been told. I plan to watch it soon.

Hi bye mama is also awesome, it's actually the 2nd or 3rd kdrama I watched and it blew me away how strongly emotional it was, a total tear jerker. So it has a special place in my heart, I think about it sometimes, even after watching 130 series after it Hi bye mama is special. I plan to rewatch it.

Smile has left your eyes /  hundred million stars from the sky,  is also a great series, but at times it was rather slow progressing.

Not seen the others ElBee listed, but I'm gonna watch some of them.


Also these are great:

Flower of Evil     (more of a thriller but a heavy emotional  drama)

... wow I thought I'd be able to add more tear jerkers, but couldn't.

Maybe this one:

Goblin  (more of a fantasy than a tear jerker but very emotional story and scenes)

 indimallow:

Thank you 

You're welcome! I hope you enjoy them (or get out the long hard cries you need from them OR BOTH ideally)! :)

Edit: You could also search for tragedies... those tend to be pretty tear-inducing. Also: currently-airing Youth of May (which ends in 2 weeks if you're looking to marathon) is the stuff Kleenex relies on for high stock valuation! :P

I initially just went w/Korean dramas, but this Japanese show's also a massive tearjerker and has a few renditions:

https://mydramalist.com/2-1-litre-no-namida

which made me remember another one that is all heart-crying of happy and sad sorts for hours (in my case):

https://mydramalist.com/20804-my-fair-lady

BTW the search option=click the magnifying glass and over on the left tap "title" then go down to "themes/tags" and things like "tearjerker" or "Tragedy" or "tragic ending" will give you some solid results.

Tearjerker:

https://mydramalist.com/search?adv=titles&ty=68&th=975&so=relevance

Tragedy:

https://mydramalist.com/search?adv=titles&ty=68&th=39&so=relevance

Then there's  "tragic ending" (don't look if you don't want to know that in advance!):

https://mydramalist.com/search?adv=titles&ty=68&th=1687&so=relevance