Creating a client portal with discounted product

Hi, I am trying to create a client portal on our website. I would like specific clients to have a page where they can fill in a password and see the same product as on our main website but with a discount. So far this is what I tried:

The portal with a password is there and the automatic discount is also turned on for the specific categories which are created just for the portal. The categories also aren’t visible on the website itself, only after login in in the portal. However, when ordering the products via the normal website it also gives you the discount, even though I’ve selected it from a different category.

When creating specific products for the portal they are also visible on the normal website in “all products”. Is there a way to keep the portal and categorys hidden so people without access to the portal can’t order with discount?