Hello. I assume you're using the app?
This should help:
Once you've opened the app, select your account picture, which will be in the top left corner.
You should get to a page with two tabs along the top, Profile and Account. Select 'Account'.
You should then see a list. Select the forth option, 'Posts'.
You should find it all there.

Hi there, You can also find all your past comments and posts if you visit your profile via the web and click the Activity tab. Hope that helps!