<human>: Can you succinctly summarize the text in 1-3 sentences?

My ex was my first real love. We were practically attached at the hip and Ive never really felt that connected to someone before or since. He left me for another girl after we went to different colleges. Ive been struggling to move on ever since. I know that that relationship is over and while I miss having him in my life, there is no chance Id go back to him. That being said, when I saw his text out of the blue saying that he still has feelings for me, I felt like my heart was breaking all over again.  I love my current boyfriend, Ive been with him for almost a year now and I could see myself being with him happily for a long time. 

So why the fuck did a stupid text from out of the blue hurt me as much as it did?  Nothing is going to change and quite frankly, Im happy with my life now. So why? Why does knowing my ex still has feelings for me hurt so bad?
<bot>: My ex texted me out of the blue. I love my current CO but suddenly everything fucking hurts. What do I do?