What is going on my external hard drive at once?

I'm desperate… My external hard drive is suddenly no longer recognized by my laptop (Win 10). I never had such a problem with the hard drive. I asked a question here earlier because something is wrong with my SD card and I wanted to use the EaseUS program to solve exactly the problem. For security reasons I had disconnected my external hard drive from the laptop and then when I was done with the SD card (problem unsolved, but it doesn't matter), my external hard drive suddenly stopped working, so it was no longer displayed. First under the drive letter "I" which was very strange, because the drive letter "G" always and then suddenly… Puff. And since then I have no access to it. The hard drive is 6TB in size and was almost full, so around 30GB were still free. Now I'm shown that it is supposedly only 1TB occupied and the rest is free… Why? I didn't do anything! I could cry and that's exactly what I already have!

Before someone comes with changing the drive letter… I've already tried that, but it doesn't work! I don't want to format or partition them either, because then everything on it will be deleted, unless everything is already gone, but I just don't want to do that.

Can someone give me a tip on what to do now?

Hard drives wear out and break - from now on immediately.

That's why you create backups.
If you don't have one, you'll learn the haret tour now why you put them on.

Try it on another device to see if the hard drive is recognized then you could rule out that the hard drive is defective

Otherwise, restart the laptop and have a little patience. The laptop first needs a moment to recognize the hard drive

And times as a tip storage media, say sd hard disk, etc., do not simply pull it off, but select the stick depending on the manufacturer and click on eject, then pull it out

What does disk management show you? Try to boot the laptop with Linux. Perhaps the disk will be recognized there.

Otherwise you can try TestDisk / PhotoRec. https://stadt-bremerhaven.de/qphotorec-geloeschte-dateien-wiederherstellen/

There are supposedly only two partitions. One around 800GB and 90GB, the rest is not shown. I'm trying to restore the data with the program EaseUS Data Recovery… It seems to find a lot…

I already have, but the same problem…
And I know that with the safe removal too.

It is also clear to me, but if you have no space to make a backup, it will be difficult.

Hmm… Maybe there are also people who are resistant to the hard way. Only you can do nothing in this case.

I'm currently trying to find and restore the data using data recovery and it seems to be working.