Email Trouble

Recently I have been getting very odd emails. They have all been regarding some type of drugs to enhance memory and such.  Get sometimes four to six per day.  This has been going on for about a month or so.  Then yesterday received an email that was "explicit".  They are all coming from different addresses, so adding them to the blocked list does not help.  Has anyone ever experience something like this and if so is there a solution to it?  It is driving me absolutely crazy.  I am also afraid of them getting worse in terms of content.

Please help me ASAP!

Yok