I should have emphasized:

If you don't have the time to have fun doing it: Don't do it.

If you do it, when you have the time for it: Sure.

Players ALWAYS ruin your preparations. So i can understand why you feel that way. Ive lost count how many stories i read online where DMs die a little inside because of the stuff their players do is always outside of their expectations.

pssst Secret hint to all of these DMs:
Embrace the players going of to their own adventures, and see where it leads them to.
It's better for the players, because they can go and do what they want.
And it's better for the GM, because they're not wasting their time.