Bronze Rank looking for Plat+ Jungle Main for advice/coaching

I started playing League last summer and started Ranked in October. I was not good because I didn't understand basic mechanics and got placed Bronze 2 a week before season 6 ended. With the new season kicking off and bringing everyone's rank down, I am in Bronze 5 and I don't want to be here. I don't play ranked much because when I do, everyone on my team feeds and I need to carry and therein lies my desire for coaching.

I started playing jungle because I was the 5th person of 5 friends to start playing league and I wasn't that good at CSing and I liked the champions that were played in the jungle. It's been about 4 months since I made jungle my main role and I don't think I am "good" but I know the basics. I feel like I know when a good time to gank a lane is, I watch junglers on stream and professional and try to mirror their jungle paths and runes/masteries, I try to watch when laners ward their brush and try to avoid it, I counter jungle and get deep wards frequently enough to put the enemy jungler behind, I ping my team quite often where I think the jungler might be and predict about 75% of ganks and where they're coming from, if I am not around to countergank a lane, I punish the enemy jungler by taking his camp or a neutral objective like Dragon, Rift Herald, or a tower' and I frequently have the most Kills, Assists, and Kill Participation in the game, but if an ADC or Mid laner is carrying harder than I am, I actively give them the kill.

My downfall is that I also have 6+ deaths on most of my games. My KDAs usually look something like 12/9/13 in a 31 kill game. I play tanky-bruiser initiator type junglers (Warwick, Skarner, Sejuani, Poppy [on Twisted Treeline mostly], and Maokai - currently trying to pick up Zac, Hecarim, and Tahm Kench [again in Twisted Treeline]). I always have the most damage taken from champions, I work as an effective frontline for my team and frequently can jump in and kill 2/3 of their backline in team fights, but end up dying and then my team loses the team fight.

Long story short, I guess what I am asking is how can I die less? Is there some big jungle secret I am missing that could push me to the next level? How do I know mid game, based on what the enemy team comp is/what they're building which color smite I should invest in; or is my smite purchase based on the jungler I am playing at the moment? I just want to be a better jungler for myself, my duo partner and my flex team.