Ranked Issues

So I recently started playing ranked again in S6 after being Silver IV in S5. I was placed into Bronze IV I guess because my MMR is so low because I won 6 of my 10 promotionals. Anyway, I started in Bronze IV and climbed to Silver V over the course of a week via a 15+ win streak to a 1-2 losses. However, now that I'm in Silver V, I can't seem to win a single game using the identical tactics I used to climb out of Bronze IV. What gives? Any ideas what I could be doing wrong or any tips for hopping back on the wagon?