Hi there for me it's been a gradual thing - part of the big problem for me was the swelling as well. the lymphatic massage I had helped with that (swelling restricts movement) the lack of muscles in part of your BOT could effect it but my dr told me that I should speak fine - which I do, my tongue might be tired at the end of the day so I might have a lisp since the old tongue is responsible for lifting the new tongue and making it work - also true - so if your tongue is tethered then imagine your poor half tongue trying to lift a tethered (possibly) swollen other half... Hence speech issues. As your old tongue gains strength it should improve, but I would maybe ask your plastics guy to remove the tethered areas. Or revise them if the intent wasn't for it to be that way to begin with. Someone else here also had issues with tethering this usually happens when a open area grows onto another open area - its a natural healing process... Usually if it's un blemished skin they've used and it's attached open end to open end I'm thinking tethering should not occur. Another someone here had them remove the tethers and is doing much better. (I remember a post about it) so I think it may and should help, but do see how much improvement you get over time first. Also swelling restricts speech as well, the exercises will help strengthen your tongue, decrease swelling (gets the circulating going) and prevent it from becoming atrophied - I talk a lot... therefore I get my exercise naturally too.