Yes, in your case I would definitely go for a speech therapist. I'm happy I went for it that a good therapist will give you techniques to use BUT they will also remind you that they don't hold a cure and that you are way more important than the fact that you stutter. They may even tell you to come to some form of acceptance that once you feel very confident then you could just tell the class or a future employer at the start that you stutter so they feel at ease. Only inhumane people will mock you for it. Be surrounded by positive and non-judgemental people who won't make you feel extremely under pressure to be a 100% flawless fluent speaker when that could have the opposite effect and yes, continue practicing on calls or find someone in person who's aware you stutter so you can strike a regular conversation with. :)