Can I get some tips on climbing out of bronze this season?

Its honestly tilting to take one step forward and 10 steps back. Its either I do good and the rest of the team falls, someone dies once and just gives up, someone decides they want to yorick jg and not buy the jg item first, or I just do bad.

Like, I know Im to blame for most of my games cause there is always something that I could have done better. I need some guidence. Hep me please D: