WD Elements 6TB external hard drive mounts as read-only, is super slow and prectically unusable

I bought this external hard drive less than a year ago, about 3 months ago it started to disconnect suddenly , even when turning my pc on it halted the login process.
But now fom 2 weeks ago, it either does not connect at all or connects as Read-only and with speed between 0 to 400kb maximum, which is completely unusable.
How should i fix this? And why this has happened int the first place? I have another wd drive , a my book version which never has this problem.

Note that this is a 6TB hard with 3 partitions and it is almost full. So i need my data and backing it up in anyway is almost impossible or very resource consuming/expensive

Hi @Hitman2847,

Have you opened a Support Case? If not opened, for more information, please contact the WD Technical Support team for the best assistance and troubleshooting: