I remember when I was fresh of the lv.30 block I was being matched against consistently diamond/master-level teams (I'm talking like, all 5 of the enemies where diamond+). Rather than worrying/caring about how my booty was being consistently handed to me on a silver platter, I learned how to play defensively and from behind. I learned how to get carried and not to be a dead-weight for me team, but rather an asset that wasn't necessarily "dominating". It was some of the best games of my life, and everyone was pretty understanding when they saw an unranked, newly level 30 on their team.
The moral of this story is: sometimes you'll have to play against people who are "better", but don't sweat it. Focus on improving and learn how to stay relevant in a game that you aren't doing amazing in. It's honestly the best thing you can do to climb.
"Learn how to get carried" <- best advice to climbing I've seen to this day