Q: FileVault always downloading/uploading iCloud drive to encrypt again

I wanted to encrypt my whole SSD drive I put in this Macbook Pro because if something happens and I lost it

BUT

EVERYTIME I log in (and it encrypted the whole thing), well when I log in it DOWNLOADS and UPLOADS my ENTIRE iCloud drive again.

I am like what?

Comcast already stuck me twice with going over the 300GB limit and if overtime I plug it in it does this, that may be like 3-4 times a day at 5-6GB EACH TIME DOWN and the 5-6GB EACH TIME UP

WHY DOES IT DO THIS?

I wanted to do my LOCAL drive, NOT my iCloud drive

HOW CAN I STOP THIS??

Need to know before Feb 7 when I am away from my house for 3-4 months WITH ONLY MY LAPTOP, not my other stuff...

thanks

phil