You've played a LOT of ranked games this season, judging from you lolking lookup, and you've hovered in Silver with a pretty cleanly 50/50 to 51/49 win/loss. I hate to be that guy, but it may just be that you're exactly where you should be on the ranking system.
I mean, sure, the league system is pretty dumb imo, but I'm pretty satisfied with how it's handled me this season. I'm pretty much exactly 50/50 and hover around silver III. I haven't played a lot of ranked in the last few months, though, and my normal rifts, as I've noted before, are consistently pitting me against high gold to low plat players with a diamond or two every other game or so.
Your normals will reference your MMR slightly, as Zero stated earlier. Try hopping on normal yoloque for like, 10 games or so, and scout them all in lolnexus. See what you're pitted against and how you do! It can be very enlightening about your individual skill level.