a) just stop worrying

b) once in a week or month click on your name, go to "Comments" tab, and click "Permalink" button under your comments to open in a new browser tab. You will see the whole subtree below your comments.

(There is a problem, that when you view a subtree of a discussion, the purple borders around all unread comments in that discussion will disappear, even round the comments that were not displayed to you.)