Stuttering isn't a mental illness, its a disability. Two very different things... This is kind of how stuttering works. But can you speak completely fluently in non-pressure situations? That's pretty rare to be **completely** fluent. Either way, you need to take the power away from the situation. You are currently surrendering to the context you're speaking in, which is the last thing you want. You need to learn to control your (somewhat unconscious) emotions that make you stutter in certain situations. Most likely you stutter in these situations because *you are afraid of stuttering*. When you speak to your friends while gaming, your mind is occupied with other stuff (forgets that you stutter), and thus doesn't stutter, or you just don't care. When you speak to yourself, you subconsciously don't give a fuck if you stutter so you brain doesn't bother stuttering. The brain is sadistic like that. At least in my experience. So you need to reach this "I don't give a fuck" state about your speech in all situations. And this isn't all that easy -- it's very easy to just say to yourself that you don't give a fuck, what if I stutter, but you have to actually believe it. Otherwise it won't work. It's your subconscious you need to actually convince. If you think about it, that's how fluent people think about their speech. They aren't afraid of stuttering because, obviously, they don't stutter. So seeing as you might have fluent potential, you should always regard yourself as fluent. And sooner or later you'll get there. As you yourself say, you don't have the physical deformity (or whatever it is), it's just a trick of the mind, something psychological, that you need to break through.