Elavil (Amitriptyline) Causing lucid nightmares?

Long story short, I recently had my first Irritable-Bowel-Syndrome attack due to extreme stress/anxiety (I started TWO schools this month!:shock:) Also being why I haven't been on since August 3rd. ANYWAYS, the doctor prescribed Elavil (Amitriptyline) an anti-depressant. It's at a very low dose (10mg) to start me out. Last night after taking it, I was laying in bed and about 30-40 mins of resting I started hearing LOUD whispers/giggling. As soon as I realized what was happening they stopped. Shortly after I was then inside my dream. Please refer to my latest DJ if you're curious what happened in it. Long story short it was a VERY vivid lucid nightmare. And this is actually the first nightmare that woke me up with a racing heart in a LONG time. I was wondering if there was any way to turn this around and make them pleasant dreams. To be honest I haven't tried any techniques yet when I went to bed due to my stress/anxiety I was having. I would like to hear opinions/inputs. Thanks!

TL;DR: Elavil (Amitriptyline) causes lucid nightmares. Any ways of turning them into pleasant dreams?