How can I do better?

I moved from Bronze 1 after placements to Silver 5, then skipped a division and now I'm Silver 3. When I first got to Silver 3, I was standing at 18 Wins and 10 Losses. I also played support a high number of times the whole way through because I feel that's what I main. I have four to five champions I can play in every role, that are current meta and most of them have CC. My concern is after watching a few diamond streams, one of them said in his replies to a comment, that being in bronze/silver means you will lose/win 50% majorly throughout trying to climb to gold? My MMR was 1,469 (18 wins 10 losses) overall 64ish % win rate and I hit a bump in the road and now i'm at 18 Wins and 19 Losses. Down to 49%. What can I do better? I want to keep climbing, and from what I hear, streaks are the best to skip divisions in silver/gold.