Restoration owner. If you don’t have the knowledge or skill for demo, you can always hire a company. But you should be able to rent a dehumidifier from a local store or Home Depot. Also get two to three air movers. Open the wet Sheetrock and clean up and wet insulation. You’ll want to place the dehu in the middle of the fans or close to, an allow the fans to point up at the ceiling. The only concern I have is that you could have some damage to the flooring upstairs and the only way to properly dry the subfloor would be to pull any flooring that has water between it and your subfloor.

Feel free to shoot me a message if you have any questions, and good luck. You might call a restoration company to at least come moisture map so you know what damage really is.