He's healthy... I'm not...

My boyfriend is a personal trainer, so hot, right? I'm a dancer. However our lifestyles are completely different... He's constantly eating and excersizing and talking about nutrition whereas I eat like a squirrel... I struggle with disordered eating and bulimia, which he's aware of... He's constantly trying to get me to eat and talk nutrition which I appreciate but I literally just can't do it... And I see how frustrating it is for him, but it's just as frustrating for me... How do I tell him I need him to differentiate between boyfriend and trainer? Help.