No advice, just commiseration.
I had carpal tunnel surgery on one hand first three years ago... Was ok for about a month, then the numbness and night time pain came back. Turns out that the problem wasn't carpal tunnel, but bilateral peripheral neuropathy... a numbness and loss of feeling in the finger tips... No good solutions, so I just live with it. hasn't gotten much worse over the past three years, but it is a life changing problem... Can't feel finger pain, heat or the sensitivity that is normal. Makes turning pages impossible, and I drop a lot of small items. Just an age thing so if that's the worst, I very happy.
I also have a trigger finger (not thumb) on my left dominant hand. That doesn't bother me at all except for the clicking sound.
The other part is arthritis... and there's little to fix that... Naproxen when it bothers a lot.
The hand pain comes at night. Doctor prescribed Gabapentin (Neurontin), but, again, only use it when I hurt a lot.
The other thing that works for night time pain (pain is always worse at night), is a wrist support. Not the simple band with a hole for the thumb, but the full cloth with metal support velcro type. Walmart sells for $10 to $30... Google "Walmart wrist splints
" for selection.
While I understand that the pain is in the thumb, I think that the full splint that keeps the hand stretched out helps. (Perhaps that's what you're using now.)
Another possible help... Specialized exercises... Utube has several for trigger thumb. I am not sold on these, but it is a possibility. It depends on whether or not the basic problem is arthritis or not, I think.
No magic potion that I know of.
Wish you the best.