Yap, it happened to me as well a long time ago.

I just got too paranoid that i am in a dream, i started thinking i am. It lasted for a week or so..
It's like you do reality checks, and you see you are not dreaming, but your mind keeps saying "this is a dream, this is a dream." And you feel all fuzzy and scared at the same time.

Just relax, do a reality check, and stop focusing on dreams for a short period !