here's my lord and savior, patrisha.
I know this comment was from two years ago, but I figured I'd still tell you how anyways.
On the top of the whole thread where all the posts are, in the top left (not the navbar, but the section right below where it says who made the topic) there is a yellow button titled New Reply. When you click on it you can fill out everything for your post, and then finish making the post there! Hope that tells you how to do it!