me (18f) and my boyfriend (18m) have been dating for about a year, we've always loved joking and laughing together. we both think dark humor is absolutley hilarious and often laugh at things that most people dont.

for context about today, im a bigger girl and ive been working out alot, trying to lose weight and stuff. i have a difficult relationship with food and today i was opening up to my boyfriend about it. i dont eat alot anymore because everytime i do i hear a little voice in my head that calls me a "fat pig" and that shit. i told him about all of it and he laughed and said "yeah you are pretty big" when he said that it stabbed straight through my heart and i have never felt so ugly. i stormed off crying and he followed after me yelling about how it was a joke. i tried to explain to him that it wasnt funny, and how bad it hurt my feelings but he just kept laughing.

im locked in my bathroom now, crying. he went for a drive or something but he keeps telling me im over reacting. he doesnt understand why im so upset but i explain to him multiple times why im upset. even if he meant it as a joke it didnt feel like a joke, and i dont even want him to look at me ever again because ill be worried he sees me as a fat little pig. he swears up and down he didnt mean it like it sounded and he thinks im pretty no matter my weight.

so reddit, am i the asshole for getting so upset at him?