File disappeared without deleting

I had a starter account and was working on a design file for some time on the web. I had also opened it several times on the mobile app in past few weeks. Today I opened it on my chrome tab (it was already open) only to see it refresh and then I am not able to access or find that file again. I have NOT deleted it, hence I am seeing nothing on the deleted files list.

Please help me as this is frustrating, disappointing and scary as the file had a lot of hard work put in in one month.