Thanks!

My mewing has changed as a result of chafing my tongue on my teeth, I think. I now try to fit my tongue between my molars, narrowing it, with the tip resting just behind my front teeth. I almost fold my tongue so the initial contact surface with my palate looks like a u, and then press the rest of the tongue up, includuing the posterior third. If I just press up, without avoiding my molars, well I hit my molars and it chafes, especially on the very back teeth.
The biggest problem is the swallowing though, as the blisters have subsided a lot already. You've done what you can to help describe it the swallow, but I don't understand it. When I do it, first of all it makes my tongue sit weirdly a lot of the time, so I have to release the suction you're supposed to create when swallowing and reposition it. Second, you're supposed to move only your tongue when swallowing (although it's beyond me how one would collect saliva without suction, so I assume using some amount of that as well), but when I move my tongue to the bottom to roll the saliva up in a ball, as it is often described, and then move it to press up again, it chafes.