Something is definitely unsolved!
After your girlfriend cheated, you need to heal the open wounds.
You do that through dialogue and rebuilding the complicity between you and your girlfriend.
If she can't guarantee you that she won't cheat again, you have to shift the way you stand in your relationship and protect yourself.
How do you do that?
You take some emotional distance and gain back a new sense of independence.
As long as you are totally emotionally dependent on her, you will get hurt.
You can't control her life if what she wants is freedom.
You need to develop a mind set and attitude in which you know you would be okay with or without her.
If she can't guarantee a commitment on her side, this means that you need a serious back up plan in case she cheats again.
Some girls will never give you guarantees. In fact, even marriage is not a guarantee.
Now, when you have enough power, confidence and resilience, this gives you the tools to pull back what you invested in this relationship when she cheats on you.
This means as well that your income, place where you live and emotional balance must not depend on her. You need to fully own these aspects of your life.
This is why working together or having a house or children together when there is no serious commitment is quite a risk.
You need to protect yourself and be ready for anything!
The full set of strategies on this topic available at:
http://vitalcoaching.com/malejealousy.htm
Take care
vitalcoach