I'm sorry to hear about the disconnections you are having, in some case deleting the diskcachearena file can help with this problem. To do this go to the SWTOR installation folder and find a folder called "swtor". Here you will find the file I am referring to, delete this and login again, hopefully it will help with this problem.
Thank you for responding but if you had read my post you'd see I've tried that already, in fact I've tried that more that once as well as the launcher/game repair options as well as resetting my internet connection many many times. it is not working.
At most I get 3 to 4 minutes of smooth play and then the 9000 error message and only on the shadowlands server.