HELP WITH WORKFLOW AND LR CATALOGUE CONFUSION

Hi,

I am a fashion photographer from America going to school overseas.  I have been traveling quite frequently and this has made me more aware of how important it is to have back ups of your files.  I am looking to strengthen my workflow particularly because I had a big hard drive scare 2 days ago.

First of all, you should know that I have a 2TB seagate external hard drive in which I store my one and only Lightroom catalogue and all of my raw photos.  I typically shoot on a DSLR in raw with an SD card and then after shooting, I plug the SD card into my local SD card reader on my MacBook Pro 13 inch (mid2014).  Then, I typically make my file hierarchy manually within the 2TB seagate external hard drive in a folder labeled "PHOTOGRAPHY" by copying and pasting a special file structure template I created inside of it based on model names/event names/dates.   Then after doing that, I attempt to import my photos from the SD to the Seagate external hard drive using Lightroom.  This is how I typically do it:

File --> Import Photos & Video --> Select the source as the SD card inserted into my computer --> Choose copy as DNG --> Select destination as a special folder within my 2TB seagate external hard drive PHOTOGRAPHY folder --> check mark to create a second copy to a LaCie external hard drive (I try to manually create the same file structure within a PHOTOGRAPHY folder on the LaCie as I have on the Seagate External) --> then I import.

This trying to manually copy everything on the Seagate External to the LaCie feels very wrong to me and I need a solution.  I wish the 2 hard drives would just mirror one another.  Should I not even bother checking the "make a second copy to" option and instead invest in a software such as Chronosync or Carbon Copy Cloner to make a back up of the hard drive itself? Or should I use time machine ?? any suggestions?

I have mistakingly been making backups of my Lightroom catalogue to the same hard drive the catalogue lives at  (on the Seagate) so technically they weren't even back ups.  **face palm**********

So anyway, I usually only edit on my laptop but I decided to try and edit on a bigger monitor at my school by plugging my Seagate into a USB outlet on an Apple keyboard attached to the monitor.  I then opened up Lightroom to edit and things were going swell.  All of a sudden I got a "disc ejected improperly" warning and then I grew slightly paranoid but things seemed to be working fine still.  I backed up my work and went home.

The next day I plugged my Seagate hard drive into my laptop and tried to open up my Lightroom catalogue and received a  "catalogue corrupted" alert.   I tried to click Lightroom classic cc's "repair" suggestion, but it was hopeless.  Everything went whack.  And then before I knew it the whole hard drive disappeared.  I have no idea what happened to it,  but I took it to get it fixed.

Yesterday morning, I reopened the LR catalog and it seemed to be functioning again, I had all my files back.

....but then tonight. I received the same warning when trying to open up my LR catalog.  I went to the backups folder and found a version of the catalog that seemed to be working still. I quickly tried to back this catalog up to another external hard drive (a porsche design named Johnny Depp) and then I backed up the Johnny Depp back-up version to the Dropbox installed on my desktop. 

I guess my confusion lies in the proper way to back up a Lightroom catalogue on 3 different hard drives and DropBox and keep them synced.  How do I keep all of the LR catalogues the same?  Is there a difference between dragging the .lrcat file onto a hard drive versus backing up a copy by using the prompt that pops up when you close LR?  Which LR catalog should I be working on? Should I be working on the Dropbox catalog , the Seagate catalog, etc.?

I'm tempted to create a new catalog as I'm afraid the backup version of the corrupted one will corrupt again.  Any suggestions would be great .  Thanks