Okay! So i recently watched my heart twinkle twinkle and totally loved the show ( must i mention i totally skipped the whole plot and just watched the chun woon tak and soon jin's part) lol so yeah as i was saying i totally loved the whole obsessive love plot.. 

I freaking loved how woon tak was already in love with soon jin and always giving her those doe eyes...

I loved how he manupulated her into marrying him and how crazy he went when she left him and how he used to record her phone calls. How he won't let anyone ever touch her and how he killed his own dogs for her...

Lol  i am pretty sure you totally get it by now but i am just so mesmerised with that whole woon tak's display of love that i can't watch any other show...

So plz plz help me here and recommend me a drama with exact kind of obsessiveness from the male lead ( no second lead plz) so that i can watch another show and get over this and focus on my exams after 2 weeks... :) thanks ..

Awww I love their plot soooooooooooooo much, wish there were more like that in Kdramas!

Most of the ones I know with crazy obsessions like that are second male leads and unfortunately there aren't that many of these either. Nothing has beaten his obsessiveness for me yet, but I enjoyed the ones below:

Beware possible spoilers ahead!

Subjectively depending who you consider male lead here, but Empress Ki has a very obsessive guy who would force the main girl to stay by his side at any cost. He is a cry baby and not a tough guy, but when it comes to female lead staying with him he is ruthless and I'd even say evil. Patience here as it's 51 episodes long and it takes a few episodes for him to fall in love.

The King's Woman (Chinese drama) - has an obsessive/possessive lead. I've only watched the first few episodes, but already he made sure the girl stays with him despite her being unwilling. 

If you haven't watched those already The Heirs, The Secret Garden, Noble my Love, My Secret Romance, Meteor Garden 1 (Taiwanese version of BOF) all have a bit of this, but in a less crazy way, the male leads are as insistent as a fly that found something smelly, go around and bother the main girl in the same way. 

Cheese in the Trap - very abnormal guy and certainly unhealthy/stalkerific attraction to the main girl, threatening people that could separate them in any way, very manipulative.

5-ji Kara 5-ji Made (Japanese drama) - a cute stalker like main lead that wants to marry the female lead no matter what.

I eagerly await more recommendations myself ;-)

Cruel Romance (A mob boss obsessed with a normal girl)

Lady & Liar (Powerful guy obsessed with a girl and he tells thousands of lies to seperate her from her lover and engage to her (The female lost her memory so he manipulates her))

Behind Your Smile (Manipulative guy)

Definitely you should watch: 

Summer's Desire

Lee Jun Kai

Too late to say I love you.

cdrama:  boss & me (title says it all)
love me if you dare ( a very picky criminal psychologist and his assistant)
love o2o (popular guy, he's quite and smart but is very detailed and is always aware and understanding of different circumstances) 

kdrama: heart to heart  ( main lead gradually starts liking her, a lot may I add)
high society: (mostly the second lead)
I have a lover ( ex husband realizes his mistake)
kill me heal me ( not exactly the lead)
moon lovers ( male  lead w/female lead, so many guys like her lol)
noble, my love  (rich guy, normal girl)
the greatest marriage ( mostly baby daddy, and a little bit of  coworker )

Bonus: Master devil do not kiss me (very rich guy trying to control and basically kidnaps the female lead)

All of these probably didn't take it as far as in my heart twinkle twinkle except master devil do not kiss me but I found that whole plot ridiculous and the quality of the drama isn't that great.  My favorites are in bold. hope this helps!

Have you tried Thai Lakorns? What you are describing sound like a slap/kiss lakorn. 

If you are interested in trying Lakorns I would recommend 

Pin Anong


Majurat See Nam Pueng

Sawan Bang (trigger warning there is rape in this one)

Mia Tuean (trigger warning there is rape in this one)

I second the person above me. Thai lakorns are a good place for that kind of story line. I would suggest U:Prince the Handsome Cowboy from Thailand (it is a lighter slap kiss kind of drama but it would prepare you for some of the crazier stuff.)
I also suggest Behind Your Smile from Taiwan. I really liked this one and finished it in like 3 days!

Thanks to all of you who were kind enough to rec. Although most of the shows i have already watched or dropped but it still helped... 

Princess Wei Young - Though it's the second male lead that becomes possessive. He becomes extremely obsessed with the female lead, and he's already this vindictive guy so he does about anything to get her. It's long, but it stays interesting with the politics woven in, and the female lead creates clever plans to stump her enemies. 

Thnks @nara but i only like obsessive male lead...because then second leads efforts seems a waste and that frustates me...

Have you tried General and I? The male lead forces the female lead to marry him and will do anything to keep her with him.

Well if your willing to watch Jdramas Hana Yori Dango Male lead is super obsessive (and posessive) but I am on a Hanadan kick since I just finished meteor shower.  Oh and when ever I rewatch nhanaDan I do skip the annoying parts and just watch Matsujun and Inouemao screen time, but I sat through it once to know what i don't want to watch again lol.

Thnks Tara and OldAnimelady for your rec....:)

Too late to say I love you.