Bratan , only reason you go on a losing streak is you playing bad .
Every game, teams and opponents are different . Only thing those 14 games have in common is you on the losing team .
Take a break every time you lose , go watch a movie , play some overthrow . You will have time to relax and you won't get matched with the same idiots in your team 2 games in a row . And don't play when you are tired and you're not in a good mood .
I started playing dota again few months ago and i climbed from 6.3k to 7.6k MMR . You can easily avoid going on a losing streak once you realize it's not team's fault ... it's just you playing bad or crying too much and making your team stop playing .