Does anybody else find it impossible to call somebody’s attention?

Does anybody else find it impossible to call somebody’s attention? I don’t know if it is just something specific to me or if there is some aspect of this type of interaction that other people would also find difficult. Whenever somebody is not looking at me or I need to be the one to start the conversation (but especially when they are not looking at me), I cannot seem to even begin saying anything. It just doesn’t come out at all. It is like a block but worse because it always happens before I can make any sound at all. It is as if my throat is caving in on itself and my words get trapped below that. I always just end up staring at somebody and praying they notice me or address me first. Once they do, it is much easier to start saying something. What can I do to circumvent this specific type of problematic situation? Does it happen to you as well?