Don’t worry! It’s actually very simple! True Node is another word for North Node. I just posted a string of posts for everyone’s North and South Node. Your North Node is in Libra, from the sounds of it. That means that Aries is your South Node.
The 7 means that Libra is the 7th Sign of the Zodiac, but it doesn’t exactly mean that your North Node is in the 7th house. In the FAQ page, I posted a link to find your North and South Node. In that, you will find out what house the nodes are located in.