Anyone have any idea what this huge white bump is?

Lilac ♡

I've had this huge white bump on the very back of my throat (not the one on my tonsil. Ent says it's a tonsil stone and it's fine) I first had it 6 months ago when I got really sick. It went away when I wasn't sick anymore. I'm sick again and now it's back. It's huge and extremely painful! Does anyone know what this could be?? It's not strep I've been tested for that last time I had it.