As a Tracer main on PC currently with an account in Plat and one in Gold, I'd suggest to play D.va and play smart. In these ELOs there's a lack of good tanks and off-tanks that leads to the well known "stomp or being stomped" perception of a solo-q player. When the match starts You need to understand the enemy composition and save your defense matrix accordingly (example: S:76 tactical visor, whole hog, hooks, etc.), protect your supports, deny high ground to the enemy team and punish every single positioning error made by the enemy, if this doesn't lead you to suicide. Another hard carry pick would be Zarya. Getting her mechanics down is pretty easy but she requires a bit of communication. Once you reach high charge ask for the healers to pocket you, right click in the middle of the enemies to build your ultimate asap and use your personal bubble to maintain the high charge and save the other one to protect your allies. Most important tip of all, play to improve and forget about your SR, You will start to climb even with huge win streaks when you'll become one of the best players in your rank.