My trick for everything I can't say is just responding however I feel I can no matter what they ask me. Someone asks my name? "hi my name is Justin" - for me saying a cold, no intro "Justin" would be tough and blocky. Someone asks me the time? It's whatever time that I can get out of my mouth at the time. When I was younger, instead of answering the phone hello I would say Yello and people just went with it. Is there a version of your name that's easier to say? Not necessarily something you'd normally go by, but just something that's an easier introduction? I wouldn't actually go by JJ, but JJ might be easier to pull of in the moment than Justin. Hope that was helpful but good luck either way. It's a process and once you find something you'll get a little more confident and it'll build from there!