I'm looking for a drama where the guy (not the girl) gets jealous and possessive easily.
Ones I seen:
You're beautiful
Boys over flowers (Who hasn't seen this lol)
Secret garden
Flower boy ramyun shop
The heirs
Also there are dramas that people tell me have a lot of jealousy but i'm not sure if I should continue watching them for example one is Full House, I'm only on episode 4 but I haven't seen any jealousy yet should I continue watching it?
You can try I Need Romance 3. 
For some reason my computer is bugging and I can't see what you've already watched, so sorry if I recommend a drama you've already completed!

I second I Need Romance 3, because he does get "jealous" quite early, only he doesn't handle his jealousy exactly the same way as other male leads do in most dramas (don't want to reaveal too much, but let's say his jealousy doesn't make him act too impulsively, he leaves the female lead some space)

In the chinese dramas Lady & Liar and Cruel Romance, both male leads get extremely possessive (and therefore jealous) of the female lead very early (way before she falls in love). The male leads in these dramas, especially Cruel Romance, were too macho for my taste, but of course that's only a personal opinion. Sealed With A Kiss has a similar character, but even more intense (he's definitely the most irrational, possessive/jealous male lead I've ever seen in a drama), if you like that type of character.

In Autumn's Concerto, if I remember well, the male lead does get jealous at the begininng of the drama. But the drama is pretty much cut in half because he loses his memory (nope, not a spoiler hehe, it's written in the synopsis, I checked), so his jealousy reappears but only later in the drama.

In Boss & Me, the hero, a large company CEO, falls for a small employee very, very fast. This drama is all clichés, but it's enjoyable because it's well executed, and it focuses purely on the romance, nothing more. He gets jealous in the beginning because her attention isn't on him, even though he's already in love.
In Discovery of Romance there's a lot of jealousy because the whole drama is about a woman torn between her current sweet boyfriend, and her attractive ex. But maybe that's not the kind of jealousy you're looking for.

In Myung Wol the Spy the male lead gets terribly possessive, but only in the latter part of the drama. For the first half of the drama he's the most unsympathetic jerk ever, but it's so satisfying to watch him fall in love, and hard (actually there's one scene that's quite disturbing where the intensity of his feelings, his possessive tendencies and his insecurity push him too far in my opinion).

In Protect The Boss the hero falls for the female lead within the very first episodes and wastes no time denying it. However his cousin and business rival also becomes his love rival, which triggers jealousy and possessivene feelings. 

I can't quite remember at what point the male lead in The Greatest Love falls in love, but I remember his chacacter falling very hard and being jealous and possessive for a good part of the show, because of a charming doctor that is also courting the female lead. These two are in some kind of romantic reality tv show, so practically the whole country ends up wanting them together, and the male lead has to fight against this ;)

I nevr finished this drama, but I believe the male character in What Is Love turns out to be the jealous and possessive type -- he starts as a player, but he rapidly falls for the female lead after tricking her, and from what I saw (I skimmed through it), he spends the rest of the drama trying to prove his sincerity and brooding because, like in The Greatest Love, the female lead and another man are on a romantic reality show.

Hope you find something you like!

oh by the way, this should be in the recommendation forum!
"oh by the way, this should be in the recommendation forum!" 

Totally agree! *moves*
well almost all dramas with second lead syndrome lol xD 

here's the ones I've seen tho:

Who Are You: School 2015
Blood (he gets really cute when he's jealous)
Cunning Single Lady
Falling for Innocence (this one is beyond cuteness)
Hana Yori Dango
High School - Love On
Itazura na Kiss - Love in Tokyo (he gets jealous more in the second season i think)
Last Cinderella
Marry Him If You Dare
My Girlfriend is a Gumiho
Nail Shop Paris
Reply 1997
Shut Up: Flower Boy Band
Sungkyunkwan Scandal (omg you're gonna have 3rd lead syndrome)
Surplus Princess
The Master's Sun
Dating Agency : Cyrano
Just you (tw drama Aaron yah is such a cutie)
murphys law of love (tw drama danson tang is such a jelly pie)
destined to love u (c drama overreacting jealous guy)
kill me heal me (kdrama who hasn't watch this. When there's like 7 personalities to be jealous of)
exo next door (they're all too sexy. Jealous of each other)
i recommend full house Thai version. 
a more recent drama is Warm & Cozy, where the male lead is childish jealous type
There is also 

Marriage not Dating
Discovery of Romance
Queen Seon Duk
Empress Ki
Too Late to Say I Love You
Loving, Never Forgetting
Que Sera Sera
Cruel Romance - the guy lead here is one of a hella jealous guy
Devil Beside You - the same as above. possesive male leads. dangggg
The Master's Sun 
Full House (much preferably the Thai version)
Autumn's Concerto
I haven't watched the Korean full house but the thai version is really really great. There aren't a lot of jealousy moments, just a few towards the ending episodes, but you'll love it. Plus, the main lead Mike is really HOT! :)