Several ways that you can get to that, so I'll just give you a couple of the easy ones:
You can go into your profile, then 'Information,' then scroll down to 'Find all content.'
Or, you can tap or click the post count number under your avatar beside any post.
If you're on a PC, that number is the first number underneath your avatar and username on the left. If you're on a phone, you won't see any numbers unless you turn it to landscape. Turn it to landscape view and tap that number and it will bring up your posts.
You can also use the "search forums" feature near the top left of this page & it gives you several options to search. Use a keyword & put your user name, even a date range to continually narrow down the search results to have fewer posts to search through.