Why cant i win solo que?

I would like actual help here not just "its cause you are bad god bronze". Ive been playing league for about four years now, in normals i am usually placed with gold- diamond players, in arams its plat or diamonds most of the time so my natural playing is at least ok. The issue is as soon as i play ranked i lose almost every game, i dont like to duo que because it tilts me faster (being bad or angry infront of friends makes me play worse/get angrier). I dont seem to be able to solo carry no matter who i play or how much ive played them. I never feel like i can rely on my teams when im in ranked. im not sure what kind of advice im even looking for but so far playing ranked at all just makes me want to give up and quit league all together. Im not trying to say im good at this game.

Update: played 8 of 10 promo games now, started 3 and 0. now im 3 and 5. 3/1-anivia died 8 times to wukong and adc fed then blamed me (i was top lane) for her opponent being so strong. 3-2 midlane dc'd 8 min in. 3-3 jungler said and i quote "im just trolling around this game so yeah". 3-4 i finally get my jungle and our first ban bans the person i said i wanted to play instantly and just says "fuck you" then spamms all chat with "no jung no top no mid no support gg ez" all game long while feeding int. and finally 3-5 was a good game we just ended up losing.