Is this an eating disorder?

i cant eat. I'm going through some difficult things right now and i lost appetite i started skipping a meal or two and now i don't eat for entire days. i already lost like 4 cm of waist and a few pounds and i feel weak and tired and I'm starting to faint when i get too stressed, its been 2 times but compared to the fact that I've always been a healthy person and i never faint it worried me. plus when i try to eat i get nausea, even with cereal, of the entire bowl i get like 2 or 3 spoons and i cant continue... i think i need help but i think it is psychological because only my boyfriend (who surprise! is the one that has me so stressed) can make me eat. I don't know why or how he does it but he can make me eat at least one full meal though i still feel nauseous when im done. Time to go to the doctor?