I keep having strange dreams about my ex- and some of them are as though he is giving me a message- could he be?

Could be, but I would look for more mundane causes before psychic ones.

Was the break up recent? Been on your mind a lot lately?

i think about him a lot - like everyday- every hour it seems
we have been on and off for over 4years- i miss hima nd it hurts

Then I would discard the idea that he's sending you messages in your dreams for now. You're thinking about it all the time and that is more than enough to make him a feature of your dreams.