I'm sorry to hear that she doesn't feel the same about you as do you about her. Now I would suggest that you focus on yourself and on beginning the healing process. Here are some tips to help you because healing a broken heart takes time and there are no quick fixes, however, 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 if you do the above steps.
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.