Trouble with thought to speech

by Christy
(Austin, TX usa)

Hi,
I have thoughts or know what to say but start stumbling and forgetting and mumbling when I try to speak it. I don't think this is stroke-like or anything, I'm in my thirties. However, I don't speak to people very often, and I'm wondering if that is my problem. I am a long-time social anxiety sufferer, and there are many times I hold great conversations, and I hold a degree, but a lot of time, and especially lately, I can't seem to communicate properly. I stumble. I can't get my intelligent thoughts into speech. Some of my teeth have shifted which now makes my S's sound snakey and I hate it, even saying my name that has an S is embarrasing. Would speech therapy benefit me? I just want to practice conversations, and I suppose diction? Where can I do that or is there an online program that would actually help as much as a real human conversation? Or do I need some type of communication therapy? Help!
Thanks.