Can't brush teeth without gagging / throwing up

For the past 4 months whenever I brush my teeth I end up gagging so hard that all my muscles contract and I'm stuck in a really painful position or I end up vomiting a little bit. Sometimes when I gag it's like there's an airbubble in my chest that pops icant really describe it. It's so bad I can't even brush my front teeth let alone my back teeth and my tongue and on a few occasions I've had to just not brush bc I physically couldn't. I've tried to Google it but all I've seen is that it's caused by two things: feeling anxious whilst brushing ( which I don't ) and pregnancy ( which it can't be ).
And it's not like this only happens in the morning, I get the same gag reflex when I brush in the evening.
Has anyone else had a situation like this? What do you think it could be? I don't even know if I should visit my doctor or dentist for this kinda problem lol