<human>: Can you provide a brief rundown of the text in within 3 sentences?

James and I have been together for over three years, we have had our ups and downs and we have been there for each other countless of times. 

James started hanging out with one of his friends from high school and his best friend, doing all these hikes and going out for beers after. He only ever invited me once, and on this hike I met this high school friend, Amanda. 

When we first started dating, I heard his best friend say something along the lines of "being so glad Jacob found someone, that way he can stop pining over this one girl." I never really thought much of it until last week when I had this dream in which I saw my boyfriend kiss this girl. I woke up devastated and blaming my insecurities and douchebag brain.

Last night I told him about the dream and what his best friend had said way back then. His response?

"To be honest, I never thought I would be friends with Amanda again"

Until then, I didn't know who this girl he was pining over was so when I told me that I just fell apart. 
 I know he wouldn't physically cheat on me, and he promises me that what he felt for her and what he feels for me is incomparable, I can't help but feel utterly shattered. I know I shouldn't be feeling like this but for some reason I feel betrayed. What if we get in a fight and he starts having feeling for her and goes to her for comfort? I don't know what to do or how to cope.
<bot>: boyfriend rekindled his friendship with a girl he had a huge crush on right before he met me. I don't know how to cope with insecurities and jealousy.