I don't really know man, just talk kind of slower than you normally do, just a bit and try it, even when you are capable of speaking faster, u got that rythm despite that speak slower, with pauses when you want just be relaxed. If you stumble after mispronouncing sth then stop for a while, breath and go back to it, either continue or say it again correctly slowly, u gotta try what feels more natural and appropriate for you. Yes man, definitely work on that slowing down, maybe you can try articulation exercises, I dont know how's it called u simply put cork or ur finger in ur teeth and u try to talk sth like that, just practice a while and see. I have the breathing exercise available if u want to send it, if it's possible over reddit.