No offence intended, but your husband has got problems... In particular, he's got problems with:
How do I know?
There's still more, though. The letter blocks are also a part of the message...
Putting all of this information together gives us the complete message:
What do we make of this?
So your husband is writing to:
Now choose your own ending!!
The name of this puzzle is
I solved the Sudoku, then learned from the other answers here, that the next step is to solve a Yajilin, a puzzle type I haven't heard of before. As these both steps are already covered in the other answers, I only give the combined solution here:
Now the last step is
This is just a work in progress.
The Sudoku looks like this:
That means the colored numbers are:
The surrounding colors looks
I have yet to figure out the significance of those numbers, but I'm working on it.
The colored numbers could be placed like this (according to their relative positions):
The positions of the red and yellow numbers are the only ...
Solved at last! I believe that the final answer is:
The completed jigsaw looks like this:
How can we find these words?
With the hints in mind we now see that in the three central 'pixels' of each tile edge that jigsaws into another tile we have:
So what does this mean? Well, realise that:
This satisfies the title since:
I'd like to share my progress so far, because I don't know whether I am on the right track or not.
With the help of the hints:
I have not been able to move an inch from there and I think I am lost.
Note: I tried to comment this but apparently there is a reputation limit for that.