The "Stream" section is the only way to find my discussions?
By "my discussions" I mean the ones in which I participated. I cannot even search in the "Stream" section.
You will automatically start following discussions when you respond to them. Duolingo will send you an e-mail when someone makes a new comment in a discussion you're following (unless you have turned that off in your settings menu). It might be useful to filter those e-mails in your e-mail program to make sure you they are easy to find and to prevent them from flooding your inbox.