YouTube Branding

I require someone who can tidy up the branding on my YouTube channel (https://www.youtube.com/channel/UCIPUFazK96b_yfHUOz-zPzA). As you can see, the banner is pixelated and the logo was made by someone with no idea about graphic design (me).

I would like to keep the same colour profile (pink/purple/dark blue). I have attached all the files I have relating to the project.

Thanks :)