Good morning! 21 week pregnant I can't brush my teeth with an ordinary…

Good morning! 21 week pregnant I can't brush my teeth with an ordinary toothbrush or an electric one. Nausea immediately arises. It started a couple of days ago, I can't even sniffle and cough either - as if something is blocking my throat and immediately there are spasms. I barely manage to drink vitamins, but they want back in,??. Toxemia was at the beginning of pregnancy until 13 weeks, not strong, just some nausea and some smells irritated me. Please tell me what it could be? Has anyone else experienced this...?