Looking for free speech therapy videos/apps for adults

Looking for free speech therapy videos/apps for adults A little background on me: I'm 23, male, I am always expected to be loud and clear, I graduated from dentistry school, struggled my way through it, stuttering has been a huge part of it, especially when I talk to patients, who aren't necessarily friendly, I also struggled to speak with friends at times, not sure whether my speech impediment is physiological or mental, either way I feel like I can definitely reduce it somehow, I need some guidance, I also tried Discord before, I sadly didn't get online much, I feel like some sort of course or a free app or YouTube video would be really helpful. Speech therapy in my country is second to none, it's a 3rd world country and 80% of people got no manners and me hiding it is much better than being laughed at. Oh and also, I was bullied during school the whole time for it. But again I'm not victimizing myself and I wanna fix it for real, I want some guidance that's all. Thanks in advance!