You can find all your posts and threads by clicking your username on the top right and then clicking "your content"
But if you're looking only for the threads you've started it's buried a little deeper and a bit clunky to get to. Click on your avatar in any post you've made, then click your avatar again in the window that pops up.
This takes you to your "
profile page". Then click "
Find" and finally "
Find all threads by okie4570"