As others have said, a silent block is one of the three types of primary stuttering behaviors. The other two are repetitions and prolongations. But however you want to describe it or talk about it, is fine. The issue isn't what you call it, but how it affects you. If you notice that anxiety and anticipatory fear triggers it, working to reduce that fear and anxiety may be really beneficial. Sure, benzodiazepenes (e.g. Xanax) can help with anxiety, but it's like putting a band-aid on the wound. A band-aid that's highly addictive and full of unwanted long-term impacts with long-term use. This article talks in depth about benzos. https://wellnessretreatrecovery.com/long-term-effects-of-benzodiazepine-abuse/ There are other ways that are safer for your body that will help you let go of the anxiety and teach you tools to manage it.