Think you need to dig a little deeper to give us a full picture.
- What is the level range you are playing at?
- What champions do you use? What role do you usually play?
- What is the average length of your games?
- Usually at what point of the game does your team start having a clear disadvantage?
- What do you think might be the reasons for your team's loss?
K/D ratio is only one way of measuring your only performance, and often it is limited in scope. Say in a game where the results are 20 v 20; a Soraka with 1/2/18 can be said to have a more positive influence than a Vayne that has a result of 4/2/4, because Soraka was involved in 95% of the team's total kills.
Knowing why you lost is a very important part of learning how to win.