I can't see what you posted in your Google Drive, but I think I may know what went wrong (aside from saving, like Apocal said). You probably changed this part of the code:
That's not actually what you need to change, but you are on the right track.
Follow these instructions:
- Click on the magnifying glass icon at the top, or go to Edit > Search Assemblies.
- In the search bar type, "SpeedUpMultiplier" without the quotations marks.
- Right click SpeedUpMultiplier in the results box and select "Analyze".
- In the Analyzer, click the dropdown arrows for Set > Used By and double click on the "OnLoad" method.
- In the OnLoad method, right click on the line of code that says "this.SpeedUpMultiplier = 4f;" and select "Edit IL Instructions..."
- Change the number 4 to a 20 and press "Okay" in the bottom right.
- Go up to File > Save Module and save your changes. Close dnSpy and you should be good to go.
Here's a picture to help guide you:
One final thing to note: anytime a patch is released (including hotfixes), the dll file will be reaquired from Steam and your changes will be wiped. This unfortunately means you will need to follow the steps again to reapply the changes. Once you get the hang of it it should go quickly though.
Let me know if that works!