it must be worse now because you introduced new chemicals in your brain. You weren't used to that drug so your brain is in a more chaotic state. This is why I dont want to try drugs and why America has one of the worst healthcare. You go in and they instantly prescribe medication without much diagnosis. At least thats what I heard, i'm not American. You should make small steps to improve your mental state then your speech will improve too because it's almost directly linked with how calm and focused you are. It's a marathon not a sprint. Also really consider speech therapy if you are stuttering 4 years then it must not be temporary.