Welcome to SR, Lilerinxx. I'm sorry about your girlfriend, and yes, addiction to pot can be as awful as addiction to anything else. And sadly, it rarely remains with just pot, not when it's at an "addiction" level.
Take a read around, especially the sticky threads at the top of this forum and it may help you understand what living with active addiction can be like. It isn't pretty and you may want to reconsider your living arrangements, but that of course is your choice to make.
There's not much you can do for her, encourage her toward a better path perhaps but in the end it is she who will have to decide to change and find recovery.
You can find a better way to live, regardless of how she is doing. Our recovery here is about us and learning to regain our balance. If you haven't already been to an Alanon, Naranon or CoDA meeting, you might want to try a few. Meetings have helped many of us surround ourselves with live support and helped us learn to work 12-steps of recovery that saved our lives.
Others will be along who have walked where you walk. My son is the addict in my life, but I understand the pain of watching someone we love destroy themselves through addiction.
Again, welcome, I'm glad you found us.
Hugs