Demoted Twice Now,Looking for Tips

So I started out in Silver 3 and I usually like to play tanky junglers,I can also fill but I usually play a jungler.So it's been about a week and I've been demoted to Silver 5 now. I was in Silver 4 and got into the promo thing 3 times but failed each one. So now I'm looking for advice on how I can maybe play better if that's what's needed. I play and alot,I can usually have some successful ganks by lvl 4-5 with and lvl 6 with . I can protect objectives and grab them whenever I have the chance with my team,the usual things a jungler does. Everything for the most part goes fine for the first half of the game,but after that things just start going downhill,I can engage well with ,usually hitting a few champions with my E and then separating them (Usually go for separating the adc from the team) but it always seems that it isn't enough,same goes for after dragging either their adc or Mage towards my team. (Unless I use my ult to drag someone away from a teamate) Each games is a new one but it just feels like end game is always the same,me jumping in,separating and then either protect my teammates or sticking on their adc,die,and then my team crumbles and we lose. I try to keep a positive outlook throughout the game and usually do but getting demoted twice in under a week can hurt morale. Any advice on how to increase my winrate as a tanky jungler? If I'm doing something wrong as or please let me know. Sorry for the long read and thank you for any advice.