I have had the exact same problem for the majority of my life. I believe it's called a silent block. And I would always force it out, and speak very quickly after. I would never stutter. I've very recently gotten over it for the most part, the past 10 days have gone by much easier, and I've been relaxing when I speak, and when I say my name (which I always struggled with) I would exhale and then say my name. Which makes it easier for me.