Actually the jungler is meant to be a player who can intermediate between all lanes and help lanes out when the opportunity arises, not babysit a lane because they are making bad decisions or getting outplayed. If they are babysitting a lane, they might as well be in the lane permanently as opposed to jungling.

As jungle Amumu in the last solo queue I played I went 8/10/31 because I jumped in to initiate, I built to be a secondary ap carry/tank using a build that I designed that worked, I placed wards for all my lanes when theirs ran out, saved carries from ganks by counter-ganking when they overextended to chase, and overall supported the team.

You have to find the champions that reflect your play style and practice with them in draft mode by yourself or with a friend.

I am good with a lot of the champs, bad with others, but I am great with these 18;

Lee Sin (Jungle)
Jax (Jungle/Top)
Shen (Jungle/Top)
Varus (ADC)
Sona (Support)
Nautilus (Jungle)
Lux (Support/Mid)
Ashe (ADC)
Ezreal (ADC)
Amumu (Jungle)
Soraka (Support)
Wukong (Top/Jungle)
Darius (Top)
Ryze (Mid)
Vladimir (Mid/Top)
Ahri (Mid)
Poppy (Jungle)
Fiora (Jungle/Top)
Alistar (Support/Jungle)

Try these champions out and see what happens, maybe they'll click for you like they did for me.

My main question on carrying myself out...

How will it ever happen when a victory gives me +15 and a loss gives me -26? And I swear it's every other game... This last one we had a Volibear with phantom dancer, IE, and working on bloodthirster...

This is not the case, you are in placement matches, after 77 games you will win and lose 12.5 per game on average, so dont worry about it.

At the end of the day elo is simply a measurement of how many mistakes you make, the being unable to capitalize on the enemy mistakes is also a mistake of your own, when you make less mistakes your elo will go up.

The reason players have trouble moving up is because they lack critical thinking skills, they are unable to look at situations and be able to understand how to respond to it unless they have seen it before(and sometimes it takes more than once to learn for them)

Stop blaming your teammates, your teammates make the mistakes they do because they belong at that elo, if you want to move up, you need to always be making less mistakes than your teammates, just because you see your teammates making mistakes doesnt mean they dont see you making mistakes.

It is very simple. Don't engage fights that you don't know for sure you will win. That is the best advice anyone can give you.

never play support / bait ur team

All of this guys games are short, looks like drophack to me.

My suggestion is to practice, learn every role, learn positioning, learn to be not selfish and help your teams. The most common mistake i see at lower elo is when a jungler invades either one of three things happens.
Your jungler is intelligent, knows either where the lanes are and the health of the enemy jungler, succeeding in the invade and escaping.
Your jungler is just invading because he can, and either you dont come to help and he loses a 1v1 fight, or there mid comes and he loses a 2v1 fight.
Your jungler is invading with the intent that you will back him up, HERE IS WHERE YOU CAN CHANGE EVERY ONE OF THESE SCENARIOS. LEAVE YOUR LANE AND HELP, that 5 CS you will miss is not worth a kill. Thats the biggest thing i notice at low elo, and it involves every lane.

Something i learned is when i was climbing elo, from 400 elo in S1, to where i am now, i would learn a new tactic, skill, mechanic or understanding of the game, and then i would go on a huge winning streak. You climb a bunch, then you level out again and you will sit there until you learn more about the game. Then when you learn more and become more skilled you will climb again

Do not play champions your not familiar with in ranked, while you may know what QWER do on there team, you dont naturally know the damages they put out, practice in draft normal

Dude ive been wondering the samething since season one once u get ur ass in elo hell it feels like there is no getting out

Honestly the best way is to duo with someone close to your ELO or around 1200. That way you artificially boost your elo and you can trust your duo to at least perform decently. Started to duo with some old friends and I have gone from 1330 to 1446. Now if you truely belong where you are you will fall behind rapidly. Granted 1446 isnt the best and is considered scrub by 1700+ but you have a better chance to improve mechanically with poeple that have a better understanding of how the game flows. IE: When to drag, baron, push ect... as for carrying yourself out. GL and I hope that you get a string of teammates that die minimally and dont rage at eachother.
Another thing I would do is take note of who you lane against. Getting good matches is a key part to victory. I dont lane top that much and had to play it, Enemy had kayle I dont normally see kayle top and wasnt sure who to pick so I picked Jax, let me tell you I got zoned soo bad and my lane was dominated. I wont ever jax vs kayle again. Something with range would have been so much better. My lane wasnt the reason for the loss but it didnt contribute to us getting ahead.(Our jungle died to skarner 3 times and he left.This is at 1400 ELO.)

TL;DR - Duo, duo, duo and Duo. Learn Match-ups. Practice in Normals not in ranked.