10 games is fucking nothing. I had a friend that went from Plat to actual Bronze V -- that's unlucky. You know what he did next? Went back to Plat I... stop being worried you're going to be a Gold player and start being worried that you're not improving

Why can you win at other queues but not Solo Queue... maybe because Solo Queue is the largest test of individual skill among all the queues? This shouldn't be a difficult question. Flex queue is an absolute joke that most of the top serious players barely (if at all) play (the Challenger ladder isn't even filled out yet after all this time), ARAM/Normals/Alternate gamemodes don't mean anything.

You have above a 50% winrate on your top 4 champions -- you were Plat V last season -- did you think you were going to win 100% of your games and fly to Challenger?

Stick with what you know how to play -- you have a lot of unique champions that you obviously don't play often that you are playing in ranked. If you combine all of those single losses on champions you don't play, you would have more than a 50% combined winrate easily.

If you don't expect to go on losing streaks once in awhile in competitive games, you're crazy.