"What should we do" vs "What we should do"

What should we do if we can't get married?

What we should do is to get to know each other a little bit more. You'll receive emails from me starting from next month.

And now I think you already know what I was thinking. When we want to ask for suggestions with a question mark, we use 'what should we do', and when we know the solution, we use 'what we should do' to make a declaration.