I’m sorry you’ve had this issue. Please consider using source control in order to guard and protect your hard-earned work.
Personally I use git because it is free and there are tons of tutorials out there to help you set it up.
As far as configuring Unity to play nice with git, keep this in mind:
Here’s how I use git in one of my games, Jetpack Kurt:
Using fine-grained source control as you work to refine your engineering:
Share/Sharing source code between projects:
Setting up the right .gitignore file:
Beyond that, to try and troubleshoot what is going wrong (and it is likely not much of a big deal going wrong), try first a Reimport-All.
If that doesn’t fix it, then I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.
Doing this should help you answer these types of questions:
is this code even running? which parts are running? how often does it run? what order does it run in?
what are the values of the variables involved? Are they initialized? Are the values reasonable?
Knowing this information will help you reason about the behavior you are seeing.
You can also put in Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene
You could also just display various important quantities in UI Text elements to watch them change as you play the game.
If you are running a mobile device you can also view the console output. Google for how on your particular mobile target.
Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong: