What really sucks is when you have like 20+ kills, less than 10 deaths, and still lose. Of course, if you complain about it then people will then tell you that you should have been carrying and it's your fault you weren't good enough to save your team (which is perhaps true). =P
I think I have never gone over 11 deaths in ranked games, and I've probably played a lot of ranked games, and it boggles my mind how some people manage to die so much.
I actually wondered if the Riven bunny was intended as a tribute/parody of pictures like that, or a similar famous picture (Wonder Woman?).
I lose a ton, and maybe you don't, so you might not want to listen to my advice. But:
If you're on a losing streak with 6 different champions in 6 different games, try doing 5-10 games in a row with the same champion instead (unless you absolutely have to play another role). That way at least you can build up some consistency with one champion, and if you can consistently win your lane then (in theory, unless you run into a counter or a good player) your teams should have a higher chance of winning than otherwise. Or something.