I had that happen to me last night!
I don't really remember the dream but after I woke up it took me over 2hours to go back to sleep.
Ever friggin noise in my house was freaking me out.
We've only lived in this house for about a month and a half so I'm still kinda freaked out at night anyway.
Thankfully after a while of not being able to sleep my husband rolled over, grabbed me and pulled me tight into his chest. Made everything all better.
I remember I used to have horrid nightmares as a kid. What I used to do is think of a happy subject and repeat it over and over and over in my head till I fell asleep. Hey worked then, haven't tried that in a while though lol