Sorry my English is little bit strange becouse it's not my primary language but can you try wow world technique? If you know blockage is coming while you speaking just focus on Vowels not on Consonants and make sure always use of nipples and ribcage is little bit tight when you speak, it's really helpful for me, and another is Speak with a pencil held in your mouth, it's painful but effective for your pronounciation, don't loose hope, try more and getting better day by day 💪🏻 And also tell me your side some other practices too