Seems like you need some practice. When you have the time do some reading while exaggerating on pronunciation, intonation, word stress and on the movement of your facial muscles in general (most important). If you have blocking issues while reading to yourself just try to exhale once, then continue in the same pace (no need to always inhale consciously afterwards). It helped me with another slavic language of the invaders, which I am sometimes obliged to use at work. Grandma may also appreciate the added clarity and improved lip work.