I can’t say my name out loud and I think it’s called blocks can someone please help me.

I can’t say my name out loud and I think it’s called blocks can someone please help me. In my professional communication class the teachers will ask you to go around and say your name to the class but when it’s my turn I just can’t get it out. I can’t say it it’s as if someone place a wall in my throat. And this only happens with certain letters and usually only my name. My name is Adam and it’s hard to get the A out. I also anticipate the moment a lot and get stressed about it if that plays a role.