This is basically happening to you because you are placed in matches against teams meant to be as good, or more difficult. the issue with this in bronze is that, everybody just loses the game for everyone else. I just looked you up, and it seems like you have a higher MMR than most others. This isn't based on how often you win or lose, it's based on how you do in each game. So naturally that can be a problem if they are challenging you.
My next piece of advice is to not duo so often, if you go into a game yourself, then your team mates and enemies ten to be ore even and balanced. (It's one thing doing team 5v5 or 3v3, but you are soloing.
- OH, also a lot of bronze summoners are txoxic, once they begin flaming, it's almost pretty much just gg. i eventually just end up sck of it and having to take an extended break from leauge.