Hello friend! What's concerning here is whether or not it's a true "stutter" or a concern of your actual brain function. I would highly recommend to first, quit the LSD and second, seek out a speech-language pathologist. There is a possibility this isn't stuttering but maybe a small case of broca's aphasia (far guess). I'm not sure how LSD alters the brain, but if you're having these significant blocks when you're talking, you may need to be referred to a neurologist. Additionally, it's important to disclose to your healthcare workers your recreational drug use as time of symptom onset. They're not going to call the police, they don't care that much, but it's information they need to know to appropriately treat you.