i’m not sure what this is maybe something with stress ?

but i haven’t been eating for almost 4 days yesterday i had a little to eat but i got full so quick and i barely had anything to eat, i felt so full to where it was to the point i felt like i had to throw up. i was supposed to get my period today but usually it’s always a couple of days late from what the app says and i had sex for the first time in a while on new years and we went about two rounds but he for sure didn’t cum in me. i don’t know what any of this is, i’ve been under a crazy amount of stress for the past couple of weeks which caused me to get a crazy amount of acne. does anyone have an opinion on what this is ?