I'm looking for tips on pronouncing sounds that I have been struggling with. I lost over 1/3rd of the right side of my tongue, including the tip.

I don't have any problems with my speech volume. I do need to work on overly annunciating words as I used to not open my mouth a lot when I talked and I now need to. The main sounds that I am having difficulty with are "S" and "Z" and in some cases (depending on where it falls in a word) sounds like "T" and "CH" especially when they are linked with an "S"

I have a bit of a wheezing sound (similar to a lisp) when I try to pronounce these. I found that cheating and making these sounds on the roof of my mouth was easier than on my teeth, but my therapist told me to use my teeth (this is a bit awkward since I lost the tip of my tongue, and doesn't sound as clear but maybe will improve with more practice).

I haven't been able to find any useful information online. So far my husband and I keep track of words I have trouble with so I can practice them regularly. I teach college classes, give professional talks, and work with the public a lot so regaining as much of my speech as possible is very important for me and my career. Anyone have any tips that worked for them or links to other resources?