we've all been there...
there are a lot of variables involved in solving this. don't get frustrated, just eliminate the possibilities and you'll figure out a solution.
first, search the old posts. this is a very common problem, and has probably been addresses dozens of times in old threads.
second, to sum it up, it's probably one of three things: bad saddle for your particular anatomy; bad seat positioning; bad shorts. there are loads of threads about saddles in old threads, so i won't get into it. check them out and if you still have questions, post again.
we've all had this problem. every time you buy new shorts, get a different saddle, or change the positon of our saddle, you go through it again. you shouldn't have to suffer to bike, so don't give up until your 'parts' are happy!
I used to dream about ice cream, Antonio Banderas, and daquiris on the beach. Now, i dream about fresh pavement...