Hi Johacao, I'm sorry you have been hurt. I'm glad to hear you are sticking with sobriety.
I tend to agree with Dee. This may have been the final straw for your girlfriend. I don't know how long you were together or how much of the 7 years of active addiction that she was with you, but she probably had a boundary.
Boundaries are important and hers may have been, if he uses again I am out of this relationship, no excuses. It's scary for family and friends to think they might have to ride the emotional rollercoaster all over again. Trust is lost. Perhaps you promised to never use again?
Regardless, she is done. So where does that leave you? Well, sober thankfully and with a full and happy life to look forward to (although I am sure it doesn't look that way right now). Maybe now is the time to fully concentrate on yourself and your life and what you want to do. To double down on your sobriety and see where that takes you.
You will be ok, it's going to take time for the hurt to heal, it won't be quick but it will happen. Taking care of yourself is paramount. Eat well, go for walks, connect with family and friends, sleep when you can. All these things will make you feel better and better able to handle this.