Have you contacted your mail service provider? The first thing hackers do is change your password so you can not access the account without a reset from your service provider..

I'm not sure who my service provider is... I contacted Shaw, who I have wifi through but they said I need to contact Mozilla? They had no idea and could not help me.

If your email address is something @shaw then Shaw is your mail provider. If it is something @yahoo them yahoo is your mail service provider. The bit after the @ in the email address identifies the mail provider, unless you own your own domain.

Oh and you might contact Shaw and ask them to employ someone with even a small brain. Because whomever you spoke to must have been looking for a part in the wizard of OZ, There is no other explanation to such a brainless response.

Anyone who knows anything about email, and I assume shaw must qualify as an ISP, knows that mail clients (Thunderbird, mac mail, mutt, The Bat! or Microsoft Outlook for example) do not set passwords for email accounts, nor do they get hacked. Email accounts get hacked via the providers web mail interface. The only one who cab correct the issue is the operator of that web mail interface.