While my stutter isn’t very severe I have found that stretching the word out while slowing the pronunciation down, and saying it “forcefully”. Just like you are doing helps me a lot. Slowing down my talking overall has helped tremendously. And weirdly enough talking with a deeper voice helps me as well. Another thing I’ve had to force myself to remember is just to not be tense, relax. Don’t respond too quickly to questions and give myself time to think about my response. You’ve heard this many times but don’t think about how other people perceive you, most people really don’t give a shit. How many times I’ve stuttered horribly trying to say something to someone and not 30 seconds later they’ve already forgotten about it.