Problem with Seagate External Hard Drive. PLEASE HELP!

I have a Seagate Backup Slim 1tb External Most updated version of Sierra on a 2015 MacBook Air I accidentally ejected it before safely removing it. Which had been done before maybe once or twice I know but never did any harm 1. After booting, I plug in the hard drive, it gets power and is spinning, not making any concerning noises. 2. Drive Icon shows up on the desktop and in finder, but the drive folder shows 0 items even though the space is shown as occupied. 3. Drive does not show up in disk utility. 4. Replaced the SATA adaptor and same outcome Any hope for me? What actually happens when you don’t safely remove? Is it permanent ? Thanks so much for your input