How can I see all my Youtube comments?
You can view all your YouTube comments by following these steps:

1. Click on the hamburger button (the three lines) in the top left of the page and click History.
2. Your YouTube history page will open. On the right-side menu, click Comments under Manage All History.
3. You’ll be redirected to your Comment History. All the YouTube comments you have made from your account will be listed here.

I hope this helps! Let me know if you have any other questions.
Is there an easy way to detect if my comment was shadow banned?
In order to see if your YouTube account has been shadowbanned, you must log out of your account and refresh the page. Then, if you are looking for a comment, sort by newest comment and if you don't see your comment at all, this is a shadowban.