Invisible Wounds are Harder to Heal than Physical Ones

I thought that it is fine to meet her with other friends after so long a time, but I was wrong. Putting too much empathy on her well being sometimes can be detrimental to my heart.
For the past year, I was living in the future when we were meeting and after she told me that we cannot be together, I was living in the past. What I want now is to live in the present. I feel empty and depressed and I want to get out of it. Socializing and comfort from friends is just temporary, I need to work on myself. At first I thought that I wasted a lot of time on this, but this is growing process. I stumbled upon a site that talks about the science of positive psychology, something which is not new to me and maybe this can help me to start believing in life and what ever I do again.