Run second site in the same VM: Is it possible?
Yes, this is possible, but take it from me as a guy who did it for about 12 sites - it gets tedious fast to manage it.

Setting up and tearing down VMs is so fast and cheap, it's simply more practical to me to create one per project. It's less to manage, and it just becomes a 'part' of the project codebase (you can fetch Drupal VM with Composer now for example, or download and keep it in a 'tools' folder outside of docroot).

Also it does not sound like you are setting up Drupal VM properly... I suggest re-reading the docs or posting more information.