I'm wondering if you have been able to make your own thread, I saw Sophie_M give you directions but have not found it yet if you have made one.
I agree it can be a confusing.
One way to do it is to scroll right up this page, towards the top right above the big light-blue Topic: Not A Happy Place you will see in tiny writing
Relationship and family issues /
Not in a Happy Place
Click on the word Forums
This takes you to the page with the big light-blue Online Forums heading
Scroll down the page until you see Anxiety in red tiny writing
Click on Anxiety
This takes you to the Online Forums - Anxiety page
Over on the right is a big green rectangle labeled New Thread
Just click on this and you have started.
I hope this is of help, I'd hate you to be so discouraged as to give up, we will get there