The guy that I went on 5 dates with just called me to say that he needs some time to clear his mind. He doesn't really know what's wrong between us but something is freaking him out. He asked if I could give him a couple days to think. I like him and am scared...

5 dates! That is nothing. Depending on your ages he might think that you are being too pushy? Relax, back off and wait to see what happens. IF he does not call in a few days then you can figure that he was not as interested in you as you apparently were in him. Then you can decide to either move on or slump into depression.