This link comes with a trigger warning. It is a text-based “adventure” game, that takes you through the paces of discovering and dealing with depression (or not, depending on your choices). Many times along my one playthrough, I recognized themes and situations I have been through myself, and thoughts and worries I have experienced.
Don't play it if you feel you might get triggered by it. On the other hand, this might be a useful link to help convey experiences to friends and family who want to understand but don't.