Trying to transfer Gmails to Proton and getting really frustrated

I am using the easy switch tools from Proton. I want my emails from Google to go in a folder (A) and the different labels of those emails to become subfolders in Proton under (A).

Everything just melds together, I am trying to "silo" the Gmails separately from my Protonmails. Can't seem to do this - Proton also somehow identifies a label and a folder as being the same thing (?) I assume as it won't let me name a folder and a label the same, this is an aside as I don't think this is the problem I am encountering.

I'm really confused as how to do this.

In the future I will totally switch to Proton and will get my Gmail to forward there, so it is important to me to keep it separate. Any ideas?