Keep it simple then lol. This is what I would say to someone who I care for and want to have a relationship with. Maybe it’s just my style but I like to add in some humor to my speech. It cuts the stress and tension/awkwardness a lot. “I know what to say..and my brain has already processed what I should say..but when I open my mouth to speak..something prevents me from speaking like a normal person. I tend to stumble over words, but I know there are words at the end of this voice tunnel and we will get there. Please bear with me. Thanks for understanding “