Stomach pain and strange vomit (22 F)

Hi people! I’ve been needing significant quantities of pain killers lately, I was on wegovy (weight loss medication) and now it often happens to me to throw up, not on that since 3 weeks or so. My doctor suspects signs of fibromyalgia, tonight I threw up a spoonful of what looked like wet coffee grounds and I woke up this morning with my stomach burning hot, I’m off my period since 2 days or so.
What’s going on? Should I seek treatment immediately? Do I have time to wait? (the “coffee vomit” was minimal btw)