D5 LF other Dia/Plat players for flex

I main Jungle and Mid. My mmr tanked a bit because i used to play a lot of 5s with my lower elo friends so I placed super low. Now, I get matched with bronze 1's and silvers against all plats teams. It's getting annoying. Especially, with bronze 1 GP supports that don't build a sightstone. Hmu