First off, congrats for getting a girlfriend. I never had a girlfriend or boyfriend, but I came really close to getting a girlfriend before, but unfortunately, something prevented us from being together.
Well, she gives you the cold shoulder right? Screw her.
Thats right, you just heard me. As harsh as it sounds, why care about someone who doesn't care about you? I learned this the hard way. I once fell for someone who didn't feel the same way. Eventually, I learned that by not giving a crap about that person, I was able to move on. Since then I resolved not to talk to her again.
Think of your ex as merely someone who isn't even worth your time. Heck, someone who isn't even worth feeling bad about! If you can achieve this, you will find freedom.