First of all I think you should ignore people that keep saying "it isn't your teams fault. It is your fault that you don't carry." They didn't see what happens in low elo.
Reasons:
- Bronze in particular is full of unskilled people and it is really hard to coordinate with them. They won't start playing defense even after being 0 3 0. not saying there aren't good players in there but there are more unskilled ones.
- thanks to op.gg and similar websites you can easily see who you are facing in current matchup. that being said low elo is full of smurfs that decided to have a fun time bullying unskilled players, and you will encounter them every few games.
Second if you are main support you should start playing champions that are game changers and can carry a lane and even a team figth. For example Taric for tank support and Zyra for ap support. I play taric against tanks or ap supports that can really snowball so he can still make a huge difference in mid late game You just need to wait for his two major items (Frozen Heart and Locket). I play Zyra against aggressive ap supports or supports like Janna that lacks any aggression in low elo.
(I had better stats last season with those champs. That being said reason for lower stats are I should have avoid ranked in weekends. Too many kids play after school ended and they just won't play safe and defensive. Or if you play during the weekends play with a duo player.)
Taric has heals, shields, stuns (and with CDR you can pretty much juggle through spells and constantly protect your team in some way.) What makes him great is ability to heal, shield and stun from far away. While champions like leona, rengar, sejuani etc need to engage into enemy team... you can use your teammates and cast your spells through them. So even if you are at the back protecting your squishy you can still protect your frontiline and at the same time stun enemy team through his positioning. If you position yourself in a good way you can easily heal your entire team and stun entire enemy team.
I go for Glacial Shroud. I'll them finish Frozen Heart or Locket of Iron Solari (depends on enemy composition). For boots get Boots of Swiftness because Taric has low movement speed. Buy Redemption and then maybe more armor or Ardent Censer for even more healing capability. For cheap runes get tier 2 Quintessence Armor (for 3 IP you will get 10 armor instead of spending 3,000 IP for 14 armor. Not really worth it. Rather unlock a new champ or something.) I play him full armor marks, seals, quints and magic resist blues. That is around 27 armor and 12 magic resist. For mastery go for Stoneborn Pact or Windspeaker's blessing.
Even after a nerf to Zyra where here plants won't auto-lock on champs if they are surrounded with minions her potential is absurd. Your plants can more dmg early than your adc. Get Thunderlord mastery. For items get Frostfang, Corrupting Potion and Sightstone (I usually avoid buying Sightstone because I look at minimap every 3-4 seconds so I have a good approximation when they plan to gank my lane. especially if they start playing aggressive if they were on defensive.) Get Haunting Guise (and built it into Liandry Torments later as your first major item) and Sorcerers Shoes. This will give you enough magic pen to pretty much avoid their entire magic resist. Rylai's Crystal Scepter is great with Liandry and you deal %precentage health dmg.
Hope this helps you.