Cannot start the sentence beginning with certain words

Cannot start the sentence beginning with certain words Hello, I'm 25M and I've never had problems with stuttering up until I was like 20. Since then I started noticing that sometimes I have a problem enunciate words starting with certain letters. So it's not a typical stuttering, but I feel like my throat is paralyzed, blocked and I cannot start the sentence with this particular word. Usually I don't have a problem when talking to one on one (even though sometimes it still happens, but way less often), mostly it's when in a group talking and having a good time jumping into each other sentences... I say only like half of the sentences I want to say. I feel like it's more when I'm nervous, but even when I'm not it happens sometimes. I still didn't figure out how alcohol affects this. Sometimes it helps, sometimes it don't. But once I had LSD for the first and last time so far, my entire throat was completely blocked, I couldn't say a single word. It was very weird, because I was in a group of friends and it was a very uncomfortable experience. I tried most of the things people usually suggest that might help. Relaxing, breathing, rephrasing the sentence, changing the order of the words, visualize and pretend that I'm reading the word, do a little hmm,... These sometimes help but they don't solve the cause of the stuttering. How is this condition called? Is it some different kind of stuttering? Why did this happen to me? I read it's not that common to start stuttering at this age. And what do you suggest that might help, please? Some exercises, or books, or seeing a specialist? Thank you