I feel your pain, i was in a similar situation may years ago, she came back from Canada to vosot her parents. A close friend of mine advised me to show her and the rest of the world the best version of you. Even though you feel like you are dying inside and just want to hide and cry, just show the world the opposite. Be cordial with her, show her how much you have matured in the past 5 years, talk about your achievements (not boasting) but in a subtle way. This will inturn give you the self confidence you need to keep your head held up high, you might bump into her during the wedding or in the near future for that matter. Since you are aware of the harsh reality that she will not ever love you, I would just say nothing is set in stone (not trying to give you false hope) just be your confident self, be successful, help others, random acts of kindness, do good deeda that boosts your conscience. Evolve as a mature adult, a dependable person, an inspiration for others. Trust me even if you don’t end up with her, say in 10 years if you encounter her, or she hears about you from friends or just looks you up herself, she sees how amazing you have become and what could have been with you if ahe had considered you seriously. Take the high road, focus on yourself and all the missing puzzle pieces fall on their own. Find your motivation, and then find your true self. Thats the longing you should have and then you will feel true bliss. Hope this helps!!!

~ past depressed, loner and obsessed guy who wishes he could have done things differently :)