First of all, with God everything is possible... Lame joke. IMHO, You can do anything you want. I don't know how severe your speech problem is, of course that makes a difference in the amount of time and effort required, but you can be a good public speaker. Excellent even. Public speaking is more about connection, and engagement, than it is about fluency. Its about communication which by nature is not about you, its about the other person. The person who is listening and learning and giving you their time to learn something, to hear something, to understand something. However, you have to have the singular mindset to make that a reality if thats what you want. Truly, that goes for everything else in life. Discipline and focus! I just agreed to do a major speech to my entire University System in April. I have no idea what I am gong to say, but I know I will rock it, even if I do stutter. I am going to be profound, funny, engaging, m and eloquent. Meanwhile my Dean knows I a stutter at times and still asked me. The hardest part was saying Yes, because I knew that I would never be able to live with the regret of saying no. Do everything: read out loud, practice, learn to love your voice, go to therapy, go to group, go out and meet people, watch youtubes, take voice lessons, practice your techniques, join an elocution club or team, join the debate club, go to an open mic, pray even, to the sun if you want... You may never be totally fluent, but at least you'll have really tried and you will certainly be better able to face the world. I'm rooting you. ​