Hello Sallylefeverbell11
Welcome to the Community.
Have you got your email in the settings? Cog>Company settings>Sales>Messages>input your email in where its showing CC
When this is filled out it should apply to all invoices, If there is nothing in the settings, are you manually editing the invoice under the customer email to CC yourself in as if your not manually copying yourself into the email and its not in the settings it wont apply.
If you have and are doing the above could you advise of your email and internet provider so we can look into this further. Thanks