You shouldn't need to use the iTunes New Feed URL tag. If you have anything in there now, remove it and save the changes.
Podcasting works like this:
1.) You create a blog post in WordPress.
2.) You upload your media file.
3.) You copy/paste the URL of the media file into the Media URL of the Podcast Episode box and click the verify box.
4.) You click the Publish button.
From there, your RSS feed should be automatically updated, which in turn will update your iTunes Store listing. Your iTunes Store listing is currently working off of this podcast feed URL:
http://impactchurchohio.com/feed/podcast/This is the default PowerPress podcast feed for your website. If you really are adding the episodes to your site the proper way, then they should appear in this feed. But the episodes aren't there.
At this point, I'm not really sure what the problem is.