Custom Theme Completely Disappeared

Hello, I’m having an issue with wordpress activating my theme. I actually had set this up from a while ago so I know the installation of everything was correct. I’ve been editing and revamping my site and all has been well up until a few min ago. I notice some weird things with my admin panel like not being able to see the .php template file I created in my page attribute area, I then went to my Themes area an noticed it was switched over to a default theme and the one I created wasn’t there there was a brief note that said the theme was broken and wordrpess is now using the default but then I tried refreshing the browser and the message was gone, all my files are still the same and in the same places as they were when the theme was up and working so I am not sure what happened or where to look at this point can anyone possibly assist, I have an index.php file in the server as well as a style.css sheet in there as well not sure why it is not picking up on this. Thank you in advance my site is under site Much appreciated!