My poodle has SA (work in progress), last year I went away for two nights for the first time since I picked her up at 9 weeks
I was a wreck
Very worried and texted my mom several times a day. First day she whined and wandered the house, looking out the window. She didn't eat the first day and freaked out at bedtime because I wasn't there. She slept with her "uncle" Simon who's her favourite person outside of me. Second day was much better, still fussy but not as worried. Did eat a bit but not her normal amount but same morose attitude
On the third day I came home and did I get a earful from her!! She barked and yipped my ear off.
Just keep to the same schedule as much as possible and don't worry too much about the eating, she'll eat when hungry. Remind your boyfriend that keeping his stress level down will help her as well and to ignore most fussing
Hopefully the time will pass quickly and you'll be back together soon