Sudden aggression towards me out of no where

Hi guys I’m looking for a bit of advice. About a 10 days ago my dog all of a sudden became very aggressive towards me. It was literally like a switch, one day she was fine with me and the next day she was snapping at me when I’d go to stroke her.

She’s been coming up to me and nudging my hand for a stoke as she’s done for years but when I then go to stroke her she snaps at my hand and has nearly caught me a few times. She will then stand deadly still staring at me. She’s been doing this with myself and my step dad. The only person she isn’t like this with is my mum.

She had medication changed a couple weeks ago and when we took her to the vet who explained it could be the new medication so took her off it. Things seemed to be getting better as she would let me stroke her after asking but tonight she went for me again and very nearly bit my hand. I’m at a point where I no longer recognise my dog and as sad as it sounds I quite frankly don’t want to interact with her at all now. Any input would be greatly appreciated. Thanks