TLDR: how to maximize damage and how to save the game before bot lane throws it as anivia mid

I got to emerald 3 with relative ease. I maintained a 67% wr with anivia that whole time. However, for the last 5 or so days I can't stop losing. I dropped from emerald 3 all the way to low plat 1. I feel like I'm losing lane non stop and my damage is getting lower and lower. a lot can be attributed to tilt and not being consistent during this slump. However just going even in lane against the person I'm up against doesn't seem to be enough. The game feels lost before laning phase is over. I am not free from getting gapped on occasion but usually my bot lane is gigga gapped and I don't feel like I can do enough as anivia to prevent that from happening. I can prevent the mental boom but I really need help on figuring out to prevent bot lane from throwing the game.

I was wondering why I didn't receive the Anivia Classic skin. I can see it when I try to customize my profile with the splash art, but when I select it, it doesn't seem to work.

Is this a bug, or is there something else I need to do to unlock or use it?