The Lady from Uncle explains how to recover your YouTube channel by first temporarily restoring your Google+ Profile:
How To Restore Your YouTube Channel After Google+ Profile Deactivation
She has also created a "how to" video if you'd like to watch how to restore your channel step by step: How To Reenable A YouTube Channel After Google+ PROFILE Deleted
A few additional things to keep in mind:
- If your YouTube channel is linked to a Google+ Page rather than a Google+ Profile you won't be able to delete your Google+ Page while your YouTube channel is linked. That's a good thing, because Google+ Pages can't be restored as easily as Google+ Profiles. But that does mean you are stuck with your Google+ Page if your YouTube channel cannot be disconnected from it and you don't want to delete your channel.
- If your Google+ Profile was suspended or terminated for violating the Google+ Profile name policy or user content and conduct policy, you must fix any issues with your Profile and then appeal to have it restored. Bottom line: if your YouTube channel is linked to Google+, you not only have to be mindful of the YouTube Community Guidelines, but Google+ policies as well.
- If you have deleted your entire Google account, rather than just your Google+ Profile, you will have to restore your Google account before your YouTube channel can be recovered.
- Once your YouTube channel is restored, you can disconnect your YouTube channel from the Google+ Profile, then delete your Google+ Profile. But you have to do it in that order!