You should now notice a new button at the bottom right - it says "My Attachments". It should bring up a list of all the attachments you used previously. This will allow reuse of those attachments. To do so, copy the "BBcode" from the list and insert it in a post. See pics below - you can do some filtering by date, etc. Note - it's generally smart to name your pics (on your computer before upload) something relevant so you can keep some track of them!