It seems you may have a confidence issue, you said you didn't have the courage to do the lines. But what if you did? Will you stutter a bit? Maybe. But no voice actor ever just started and they were amazing, it takes practice. For you it may take a little more effort then others but if you truly love I think you should pursue it regardless of your fears. You cannot define yourself by your stutter. Maybe you can find such a tone or voice you can talk in that makes it easier to say the lines then practice practice practice. I know nothing about voice acting but, I've stuttered severely my whole life and I once also had that limiting belief. The truth is, what's holding you back is YOU, not your stutter. Like you said, you know you would've rocked it, sometimes if you really want something your going to have to endure a bit of pain to get it. I think your stutter actually sets you apart from your peers, seeing someone pursue voice acting with a stutter is inspiring and I think most people will respect that. I believe in you, but it takes believing in yourself first to make it a reality. Message me if you'd like, I'd love to talk to you