Terrible Burning Lump Sensation In Throat, Chest, Took Prozac. What Is Going On?

I have been taking Prozac daily for about a year and Vyvanse almost-daily for a few months. And it has been fine up until this week. On Thursday I experienced this terrible burning lump sensation in my chest and throat about 10 or 15 minutes after I had taken my meds. It was very uncomfortable and painful, it felt as if there were a pill lodged in my throat. However, I tried eating, drinking, stretching , self induced vomiting , and it didn t help. It started to gradually subside about two hours after I took the pills. I figured I had just gotten a pill stuck, and though it d probably not been there long (considering my efforts to dislodge it), the burning persisted a while. I thought it was a fluke. But then it happened again Friday morning. And it s happening right now, on Saturday morning. What s going on? What is it that causes this to start happening?