Cannot read and write external hard drive when I was able to do so before. Disk utilities doesn't help

I've been using this external hard drive for a long time and i've been able to read and write it. Last time I modified it was at 8:35 AM TODAY. Suddenly for some reason now (10:49 AM) i can't read and write it and make new folders and all of that. The permissions says "read only". I don't' know what could have happened other than the 4 port USB thing I'm using for my other hard drives might have done something I'm not sure. I tried erasing it from Disk Utilities. The message "Erase process has failed. Click done to continue". But in the Finder Application the drive isn't connected anymore. I tried the "Partition" option but it's greyed out. I've inserted screenshots of the whole thing. What can I do? I'm so confused. I've copied everything to a different hard drive to make sure all the information is safe. But I'm pretty bummed that I can't use this hard drive now. My computer is MacBook Air in the macOS Mojave 10.14.6. version.

Before erasing, You can see that the drive is connected from the Finder app.

After erasing. The error message shows, and the hard drive is no longer connected?

If anyone can help I'd really appreciate it so much!