I know this isn't what you were hoping for, but ultimately what you're doing is what would be taught to you in speech therapy. You already figured out a technique to physically help you, which is not nothing. On the more sentimental side of things, I'd say try to nurture compassion towards yourself. When we shift our minds away from frustration and shame and move towards compassion and patience, things naturally get better. I know this is vague and seems difficult to do, but if you try to notice when you get ashamed or frustrated at your stutter and make a point of nurturing compassion and understanding towards it, it will ease your blocks.