Most Helpful Girl
If she is seeing someone else there is nothing you can do about it.
But yes! you must not contact her. I did not contact my ex and he starting reaching out barely a few days after leaving me in tears. I did not reply his first messages emails etc, and started replying. I call this the don' initiate contact + the limited contact rules :)
But to know how to act and what to response, look up coach corey wayne on youtube! He helped me a lot!
I had to adapt some advice since I'm a girl...
Most Helpful Guy
The advice you should have been reading is to FIND A NEW FUCKING GIRLFRIEND.
No contact has ONE purpose -- to permanently eliminate another person from your life. The people who are telling you to try it for getting an ex back are teaching you to be emotionally abusive.
Let me say that again. Emotional abuse. Manipulation. Using no contact to get someone to "like" you again is Emotional abuse. A form of violence.
Get a new girlfriend. Talk to new people.