Is there a non toxic way to lower the Normals MMR?

For me it doesn't work the way I want. My rank is Plat 1, but I mostly play Normals and get matched against d2+ players (usually at least one grandmaster/challenger). On top of that most of them are in a full premade. It's EXTREMELY annoying to play against them. So many times I wanna chill as a support and 4 enemies keep diving us in a way that only high elo premades do. Ironically, it's easier for me to play ranked matches. I checked a site that shows you your MMR (I'm not sure how accurate it is) and I'm at ~0.2% Top players in Normals, but only around Top 10% in Ranked. And my winrate is pretty much the same for both modes (around 54% iirc).

/r/leagueoflegends Thread Parent