yeah its always hard for ppl who arent emetophobia, or even have any type of mental disorder, or expierence with it, its hard for them to try to completley understand. But he seems like he is making an effort to which is good.
When i told my b.f about my emet, he said "wow now everything completly adds up!" made me laugh actually..but hes awesome about it and understands as well as he can. although he can get a bit fustrated at time, which is understandable..its a part of your life, and if he wants to be in yours, hes going to have to accept it.
Just be up front, maybe even show him a few pages on this site. Most emetophobics tend to feel embarssed when they feel sick or feel they may v*, so its completly normal to wanna be alone. Just be honest n tell him exactly how you feel.
Go confidently in the direction of your dreams. Live the life you have imagined.