Can't get out of Bronze cuz of team

Now, I'm not a good neither a bad player. I have good and bad games, but my highest division was S5 and since then I was demoting and demoting and demoting until i got to B5 right before Season 7. Reason ? Then I was kinda bad somtimes and my team was as bad as me or worse. I played the game for 4 months. Then when I try to get from B5 to B4, which I did and stayed there for ~1 day, winned 2/3 promo games. And tried to climb up. I got B4 carryed by a friend in S4, which also was demoted. Now I am in god damn Bronze, cuz you get to play with people, that are way way way below bronze skills. And that a circle of loses... It makes me wanna kill myself right now cuz of the time I dedicated this weekend to LoL, to be promoted just to find myself playng with toxic ppl, ragers, feeders, people that blames everyone with 0/25/5. Riot please help. Maybe a way to get not cancer, not feeders but normal people to get play friends, even if they speak other langauges or are main ehat you are that would be better to get out from btonze, where you will get better player to play with. I know some people will say I overestimate a bit, or divisions are based on your skill - NO. Divisions doesn't determine your skill. A diamon player sayd to that same silever4 friend that he player like Gold-Plat.