I understand your situation better and I am sorry that he will not talk to you. If he really loved you then his feelings would not change so quickly, especially not in 2 weeks, however, he could be repressing them which could be why he began dating this other woman. He also could have wanted a relationship that is not complicated, but the reality is all relationships are complicated on one level or the other and they take work to succeed. I think the best thing to do now is to let him go because he is intentionally choosing not to respond to you. Also, I think you should begin the healing process on your end. Healing a broken heart takes time and the below steps will help your broken heart heal.
1. Get a positive support system in place for yourself which includes loved ones and friends you can trust and share this extremely painful experience with and who will also help you through it.
2. You are dealing with various normal emotions due to being separated from someone you were once so close to, therefore, if possible, I recommend going to see a therapist, counselor, etc., in person on a weekly basis to help you deal with this (-especially any guilt, hurt, confusion, frustration, anger, etc. that you may naturally feel). If you are religious, your place of worship may have free counseling available (-many churches have free counseling).
3. Write down how you feel in a journal. Then close out each writing session by meditating: close your eyes, breathe in deeply and exhale. At the same time think of something peaceful. For example: a bright blue ocean with deep rich blue waves gently whispering against the beach. Meditating will help you through this difficult time and it will also help you to heal. It will take some time, but you will get through this very painful and difficult time.
4. A book I recommended to my clients dealing with the same situation, which they found helpful, can be found by clicking here:
I know it doesn't seem like it now, but slowly and surely you will be able to overcome this.