why wordpress hosted site showing up self-hosted wp?

Hello,
I have two sites, one hosted by wordpress and one self-hosted. When I search on Google with my site name “kandkmatwick”, my site https://kandkmatwick.wordpress.com site comes up before https://kandkmatwick.com. Why is this? I would like to have my self-hosted one, https://kandkmatwick.com show up first. Is there a way to do this?
Thank you!
Kelsi