Hi there well I had similar surgery as I have mentioned before - everyone heals at their own pace but six weeks is usually optimum for healing. With regards to the neck dissection - you may always be numb in certain areas, I had ten more nodes removed, than you but I can feel pressure on my neck from under my ear but no real sensation and it's been 15 months. Did your dr give you visible neck stitches? I was shocked when I found out that the don't routinely hide them, my dr. God bless him gave me invisible stitches so it's healed to a fine thin line. My neck also still feels tight - now I had radiation so that likely has some bearing but to touch it is soft and looks completely normal, even the scar from my trache has smoothed out

I can't comment on the tongue - much - because I did have a reconstruction, but the burning is likely healing an nerve regeneration. You will heal just give yourself time. Good luck and take care,