This is a question more than advice, but it's quite clear that Riot's matchmaking throws you against opponents of or higher than your level, and with teammates at or below your skill when you're in the promotional series. My question is how can I succeed and make it through a promo AS A SUPPORT. The support role being as dependent on their teamates as they are, I feel there should be some way to succeed and prove your worth when your team is terrible. What can I do to make it through this? I'm silver division v was 10-5 until i hit the promotion matches, now my lead's been vaporized by terrible teammates feeding lanes.

play taric, best support XD

nah but in all seriousness your picked the only role sombody can viably main in ranked, i suggest trying to branch out to atleast 1-2 other roles

I suggest you don't solo queue. I could ADC for you if you wanted. HMU and I'd love to play with you classic SR for you to gauge where I'm at.

I main support and I agree totally. If I solo que, I will lose non stop because I have to rely on my team. If I get a lousy ADC (which happens all to often due to people picking it first because they have "pick order" and get countered) then bot is lost, and they blame it on a bad support. If I duo with friends who play ADC, I typically win those games because I know my ADC will be fed and protected.
I recently started rank, and am still in bronze. I have made it about 3/4 way to bronze 3 when I decided to try some solo que's. As you have probably guesses, I am back in bronze 5. It is hard to play support if you have no 'support' from your team. We are a different type of carry, and people don't understand exactly how support works. I seriously believe some people honestly believe supports are supposed to have god mode cheats on hand to keep them from dying, because we are afterall the support.

If you are going to support during your series and it means a lot to you to advance, try and duo queue. Having a solid bot lane can make all the difference come mid game.