Since, you know, you have to play the most difficult role in the game
IMO i don't think jungling is the most difficult role in the game. The great thing about being a jungler is that you don't have to worry about trading and harassing with your opponents. You have the the freedom to farm securely. Unless someone invades you, but there are many options to counter that. i.e wards, calling your team, invading the enemy jungle to recover lost camps, or if you are playing a jungler that is strong at dueling or you know very well you can outright kill the invader.
You get blamed when your team does bad?
Well it happens, but you can always mute them. Or you can take their "advice" and maybe improve your jungling, but if they are out right flamming at you for no apparent reason just ignore or mute and move on. The most important thing is not to engage in a verbal battle, there is no point and the amount of time you spent typing could otherwise be used for other things.
If one thing goes wrong in the jungle for you (like losing your first blue to a Xerath W.........that just happened to me), you know you are completely, and utterly screwed?
It's not the end of the world. you won't be completely screwed, there are 5 other camps you can farm to maintain your experience levelled with everyone else. Also when you give a lane a gank, you can take some of their farm, as commission for your services.
You feel completely, and utterly helpless as you watch all 3 lanes just get steam rolled (without jungler intervention)?
Well you play a jungler so that you are not utterly helpless as all the other lanes fall in to pieces. The joy of jungling is that you wield the power to change the tide of the lane, even when the enemy laner is superior. If all the lanes are falling to pieces and you can't help all of it at once, you can focus on a single lane to watch over, that you think will have the best carry potential.
You have to be that backbone for your team, but if your team can't do their job, there is honestly nothing you can do to help them or yourself?
It can happen, sometimes your ability to help your team do their job is beyond your capability. e.g. Your AD carry doesn't do any damage because he/she didn't build efficiently and your a tank jungler Naut and can only tank so much damage. The only you can do is maybe give some advice on how the AD carry can build efficiently or focus watching over the AD carry in the early stages of the game.
You have to be watching your map for 90% of the time, and if you make one wrong decision in a direction you take, it could cost you the game?
Well in lower elos one wrong decision doesn't make or brake a game. Just try to not get tilted and focus on your job and you will be fine. But for higher elo, then i guess yeah your screwed if you make a wrong move, as you will be punished severely by the enemy team. An easy way to keep high map awareness, especially during the early game and if your playing slow clear junglers like rammus or amumu or malphite, You can leave your champion to attack the monsters and activating your abilities when the cd is off while you roam the map with your camera as you wait until the monster dies. Make sure that you don't get invaded tho.
I am not the best player out there, but these are just my experiences. Jungling is my favourite roll and is the most rewarding role to play with the highest carry potential. The highest rank I achieved in league was Gold 5 (saddly after season ended) back in season 3 from only playing jungle and adc.
