Possibly Shen isn't the champ you want, when you're looking for heavy impact / carry potential in low elo.
I think it's much easier with champions that punish the enemy team when they get the ball rolling.
Regardless.. I think " Elo hell " applies to certain types of people who have a mix of things going for them.
Bad MMR + Lack of ability to carry + Tendency to go off in chat + A lot of other sht that just brews this perfect recipe for keeping a consistent 49% winrate ( slowly dropping )
Despite what you're trying to convince yourself, in my opinion Shen might be your crutch playing at that MMR.
And I've done Unranked to D5 many many times, if you were truly a Diamond level player or even Plat. Your stats would look a lot better than what they are now and your WR.
I don't know what else to tell you if you still believe you're a Diamond level player, who's 840 games into Silver 2 at the end of Season 6.
Shen can taunt ult and possibly split push.
But all in all, his kit seems more like the supportive / tank type. At this point, it would just seem to me like you're supporting these Silver / Gold MMR teams, which is something I would definitely advise against doing if you wanted the idea of you being a Plat / Dia MMR player to actually become reality.
I urge you to try something a little different. Maybe Trundle / Trynd / Kayle / Teemo
Teemo's taken me to Plat 1 when my smurf was still in Gold. Obviously he's a bit trickier to use after that, but my point is.. he's effective in lower levels.
Kayle is just the ultimate AoE shredder, paired with her constant up time of E and Runaans with passive. And when you hit level 6, most of the time you basically win all trades top coming out of the fight with a kill and have the ability to 1v3 1v4 the enemy with everything pieced together late game.
Trynd's split push is just massive in low elo and especially when everyone's mechanics are arguably horrid, they'll more than enough times step into range to die to your massive crits. Slow + Gap closer = Good bye squishy carries.
Trundle could be more of your play style as that control tank, but at the same time he's a beast duelist in lane and offers nice damage while at the same time being tanky. Also a great champion to just zone carries and at the same time peel for yours.
I'm trying real hard to shine some light for your situation and hopefully offer a different POV that may yield better results than 49% Winrate Shen in over 600 games. I'm not trying to offend you by calling your stats out, but seriously the reality is.. it doesn't seem like what you're doing is helping much to prove your point that you deserve Plat or Diamond this season.