Help please

So this is the second time this has happened, I have or start eating food and then it starts making me heave during it I run to the toilet to be sick but it’s just heaving, any ideas on what this could be, I don’t eat a lot in general anyway but this is the second time it’s happened also my back tooth or jaw or gum in hurt to the point where I can’t grit my teeth feels like I’ve bruised it