Client Portal for Vendors?

Client Portal for Vendors?

Our work is heavily connected to Vendors as a road construction company and our clients are very few and they are government organizations so the Client Portal isn't ready beneficial for our clients. But it would be great for our vendors as they can check their balance with us and compare their records against ours as we usually run into the problem of unrecorded transactions on their part.

If that cannot be done or isn't going to be available in the neat future, then can you help me with this:
I have put my personal email as a contact for a vendor and enabled the Client Portal for that vendor just to see if it worked for Vendors. I received the email and logged into the Client Portal and discovered that it doesn't work for Vendors.
Now I want to disable the Client Portal and remove my email as a Vendor contact, I couldn't do neither!
Attached is an image of the message I get when I try to delete my email.

Please help.

Thank you