Try doing voice therapy that strength the vocal chords and practice saying all the phonentic sounds in your chosen language (speech sound stimulability) to improve the coordination of your speech articulators. Specifically your problem sounds. Spend 30 mins to an hour each day practicing them. Focus on improving your awareness how you are producing these sounds. Correct any deviations from how their supposed to be articulated. There's research that shows that speech sound stimulability helps improve the vocal motor coordination between speech sound. Also the Hollins fluency system does something similar plus many other speech therapy clinic have patients practice saying the different speech sounds. Because over time, we learn to alter the speech sounds in order to overcome blocks and develop a havit of saying them incorrectly, leading to us making them harder. So retrain your speech sounds along with your breathing. Start breathing through your nose and using your diaphragm when speaking.