A speech therapist is the specialist we usually see when there is a problem with speech. As well as correcting mispronounced sounds, they also work on the correct position of the tongue in the mouth, which speech also depends on. This specialist is an essential part of any treatment aimed at correcting an incorrect tongue position and infantile swallowing. They give the child a series of exercises to train the tongue and check that the child learns them and does them regularly. Of course, the orthodontist can also give exercises to help correct the tongue, but in my view the best thing for the patient in these cases is collaboration between the different specialists.
This answer is for general information. Your own case needs an examination by an orthodontist.