"My feed" displays images from other creators that you follow, so you need to unfollow a given creator to remove their images.
To unfollow a creator:
Click on any of their images in the feed, which will pop up a detailed view
Hover over the purple "Following" button next to the creator's username
Click the red "Unfollow" button that will follow and then reload the page for the change to take place.
Thereafter, the images from that creator should disappear from your feed.