Hey there! Maybe I can help - I'm a high plat / low diamond support main. Here is some advice for you on carrying games and winning as support:
First and foremost - always remember that you are 1 of 10 players to influence the game outcome, if you divide that down to percentages, that means you determine 10% of the games outcome. If you look at it specific to your team (1 of 5 players) then its 20%.
Either way, There will be countless games that you are unable to stop the outcome of - this is just part of big team games like League. This is why a winrate of 70-75% is considered 'pro' level. Even the best of the best usually only have a winrate of 60-70% over hundreds of games. My point is this: Do not beat yourself up over every loss. Instead of focusing on winning or losing, focus on your own play, and if you could've played that game better.
Now... lets talk teammates
Your best chance of winning a game as a support main is always with your laning partner. Your first step should always be trying to get them as fed as possible and protecting them at all costs. Sometimes you're paired with a player that you don't mesh with - or that you think is pretty awful. In these cases, I have 2 strategies to try.
1.) Take over the lane, and start making yourself as powerful as possible. This depends on who your playing to some extent, mage-supports tend to scale better than someone like Janna. This is why Janna players frequently DuoQ, because it ensures they have at least 1 strong ally. The main takeaway here is that CS is power. If you dont think your ADC is competent enough to even have a shot at carrying, then the CS is better given to you, since you know what you are doing.
I have won countless games by 'taking over the lane' .. I hate to do it, but if my ADC proves completely lost, then this can save the game.
Good supports for doing this:
2.) As for the 2nd option, pay close attention to the 3 other players in your game, and try to make a decision on who you think the best of them is. Support the player(s) that you think is MOST likely to carry. Believe me when I say that ANY role can carry it. If your mid is 4/1/3 - That's pretty freaking good - Start to follow your Mid around, keep them alive. The ADC will break off and get farm on his/her own.
or 
) if my team cant do any damage and they just feed their asses off 0-10? I cant protect them because they just run in middle of their team alone against fed enemies and die in 1 second. I feel like I cant really do anything else than put useless shields on them and watch them jump in and die. Should I play supports that can do some dmg like Lux? Or should I just stop playing support and play a role that can carry better. This happens way too often and Im wondering how a 0-13 Ww can even reach anything else than bronze5. Warding doesnt help because they still just push the lane to the turret and have no reaction when jungler can be seen on the map or when I spam pings to back off. Of course this doesnt happen every game but when it does happen how can I win the game or is it just a instaloss?
into 
Q to giver her a free kill, waste her