What happend to dota players on rankeds

Hi. So, before we start I am not a BabyRage or PJSalt player, but something definitly happend to all dota 2 players in my team. I almost every time watch a replay of lost game and analyse my bad decisions ( mostly I am carry player ), wrong item build or even wrong carry pick. As we all know in every ranked match we see legion commander, invoker, OD, spectre, omni, zeus, bh. But my biggest problem is, this "worse players" are in my team almost every game. When I play support ( always as 5th cause my 4th position is jungler LC ) I try to buy always wards when I have money or they are aviable, if we play aginst inv heroes I always buy as many sentry and dusts as I can ( thats why I got brown boots all game ), but when I play carry ALWAYS my supports focus on buying items which we won't need ( for example we need dust, but no1 is buying this dust, they just save money for "early" game hex ). In my last game I had brood and pudge on double offlane aginst solo slark ( ofc they didnt make it, but enemy has lc, and this lc had like 50 dmg stack after 5 mins when she bought dagger ). The biggest problem is, when we play aginst spectre, noone is even trying to gank her, cut her from farm by early pushing towers, but when I or my teammate picks her enemy has like insta communication about the picks. I am even trying to talk to them when we are picking, but mostly I am typing to myself, after on last pick I get random and question "SB SWAP?!?!?!" ... holy shit man. Do you have any tips which help me get out of this dark side of dota? 2 days ago my mmr was ~4,9, now its less then 4,7 ( after every game I watch replay and trying to fix this next game, but every next game I get same teammates, same problems and everything looks same. Last game as well I had a brood which ofc said "ok guys, fuck this game, enjoy your -25 u fuckers" ... yea 4,6k avarage here. I don't really know what to do. This patch is about communication and picking right heroes, but every time I try to suggest a hero I get flamed. What's your suggestions about that, or its just 10 games in a row lost after 10 won or smth. Plox help guys, I dont even know what to do. Mb w8 for next patch... dunoo.