Welcome to the club

The naughty buggie problem I know of is fixed on re-entering the game, so if you do not have any partial structures anywhere, I am a little stumped for the moment. Sorry.

The only other thing I can think of at the moment is to try to manually breed the villagers, to kick start them into building, but I am sure that you have tried this.....
Barbara, or others who have had more experience, should be around soon, so I'll be interested to see what they suggest
Good luck