On 16th September my email system was hacked and I am unable to access it - can you help please?

First, I regret that your email was hacked. My recommendation, at least for now, is to ignore Thunderbird and its setup. Instead, establish a new email account with a provider that offers a user-friendly web interface. My recommendation is outlook.com. The setup is easy and the web interface is excellent. You may find that you don't need Thunderbird for your email activities. It has filtering if desired, and you can create addressbook and add folders as needed. I have made this recommendation to other friends and they have been very content with the Outlook interface. This solution will simplify your email life. I am older than you and I speak from experience. :)