Excel custom tab & group suddenly disappeared

Help!! I work almost all day in Excel spreadsheets so I had created a customized Excel tab and group and even added some things on the quick access ribbon that had my most used things. It was there this morning and then just a few minutes ago when I opened a spreadsheet it's now gone. I went to file and then options and customized ribbon hoping it would be there but it's not. How can I get it back? I know I can go back and redo it and I remember the majority of what I had on there but I'd rather try and get it back. Please help me! I thank everyone in advance for their help and advice.

I did try that but it didn't work. I ended up having to re-created my customizations but I now know to export them whenever I update so that's what I will be doing from here on out.