@lyarrow, here’a what I do (all on iPhone):
Upload photo to Media (under My Account).
After uploading, click on the photo so it opens up in its own page.
Press on the photo until options appear. Choose Copy.
In your forum post, click on Img.
In the url box, delete the http text and paste your own link.
This puts the photo in the body of the post rather than as attachment.