I can’t give you any definitive advice because I struggle with the exact same thing. All I can tell you is that you’re not alone. I’ve been doing speech therapy recently and I’ve been able to say my name fluently a few times in the last couple weeks. I take a diaphragmatic breath, then minimize pressure in my mouth before saying “David.” But it took weeks of therapy and this is just what worked for me. You’ve faced a lot. Stat strong.