|Spammers often spoof your email address if they can get hold of it.|
Go into Google, type in your email address and see if it finds it.
If so, you'll continue to get spammed to death and can only cure it by changing your email address then never leaving it in open text on the internet.
In any event you need to run your virus checker for starters. You could also try scanning with MalwareBytes freebie, as this often picks up what other programs miss.
Please come back and let us know the outcome.