Apple Mail not working on Mojave

Hi,

Since this afternoon my Apple Mail has stopped working.

Initially it would not send emails, now it doesn't even connect anymore and shows all accounts (2x gmail, 1x icloud) offline.

Connection Manager spins for over 5min before finally saying all accounts are offline and the only suggestion is to fix account setting in Preferences.

However, when I open Preferences there are no Incoming/Outgoing settings fields and if I open the 'Advanced' session or 'Edit smtp settings' there are no server listed. If I try to add one, it disappears as soon as I save it.

There is no option anywhere to check/edit Incoming server.

All emails are fine from iphone/web mail.

I have been through all self-help from the past on Apple website/this forum and several blogs with no luck.

I tried several times to delete/re-add the accounts again with no luck.

If I try to add the accounts manually instead of using the Gmail setup in Apple Mail, it gets stuck on a spinning wheel until I force close the app.

I don't know what else to try.

I'm on a Macbook 2017 with Mojave 10.14

Any advice????