No. You have not been hacked.
“From” spoofing means faking the “From:” address on an email to make it look like it came from you. To do it, spammers don’t need access to your account at all. I’d say that 99.99% of the time it has nothing at all to do with your account, which is quite safe.
They only need your email address.
While your email account and your email address are related, they are not the same thing.