Listening to yourself as in on a recording or in your own head? And is it a buzz or a natural vibratto?
It could be that you need better breathe support, so look up some excersizes on that. And I've heard that a teaspoon of oregano oil gets rid of the phlegm that clogs the throat and cann create a buzzy noise. I'm too wary to try drinking that stuff, but if it works, do tell me!